Switch to martinohmann difflib fork and colorize diff output

cmd/gmailctl/cmd/apply_cmd.go

@@ -16,6 +16,7 @@ var (
 	applySkipTests    bool
 	applyDebug        bool
 	applyDiffContext  int
+	applyColor        string
 )
 
 const renameLabelWarning = `Warning: You are going to delete labels. This operation is
@@ -51,15 +52,19 @@ func init() {
 	applyCmd.PersistentFlags().StringVarP(&applyFilename, "filename", "f", "", "configuration file")
 	applyCmd.Flags().BoolVarP(&applyYes, "yes", "y", false, "don't ask for confirmation, just apply")
 	applyCmd.Flags().BoolVarP(&applyRemoveLabels, "remove-labels", "r", false, "allow removing labels")
-	applyCmd.Flags().BoolVarP(&applySkipTests, "yolo", "", false, "skip configuration tests")
-	applyCmd.PersistentFlags().BoolVarP(&applyDebug, "debug", "", false, "print extra debugging information")
-	applyCmd.PersistentFlags().IntVarP(&applyDiffContext, "diff-context", "", papply.DefaultContextLines, "number of lines of filter diff context to show")
+	applyCmd.Flags().BoolVar(&applySkipTests, "yolo", false, "skip configuration tests")
+	applyCmd.PersistentFlags().BoolVar(&applyDebug, "debug", false, "print extra debugging information")
+	applyCmd.PersistentFlags().IntVar(&applyDiffContext, "diff-context", papply.DefaultContextLines, "number of lines of filter diff context to show")
+	applyCmd.PersistentFlags().StringVar(&applyColor, "color", "auto", "whether to enable color output (must be \"auto\" or \"never\")")
 }
 
 func apply(path string, interactive, test bool) error {
 	if applyDiffContext < 0 {
 		return errors.New("--diff-context must be non-negative")
 	}
+	if applyColor != "auto" && applyColor != "never" {
+		return errors.New("--color must be \"auto\" or \"never\"")
+	}
 
 	parseRes, err := parseConfig(path, "", test)
 	if err != nil {
@@ -76,7 +81,7 @@ func apply(path string, interactive, test bool) error {
 		return err
 	}
 
-	diff, err := papply.Diff(parseRes.Res.GmailConfig, upstream, applyDebug, applyDiffContext)
+	diff, err := papply.Diff(parseRes.Res.GmailConfig, upstream, applyDebug, applyDiffContext, applyColor == "auto")
 	if err != nil {
 		return fmt.Errorf("cannot compare upstream with local config: %w", err)
 	}

cmd/gmailctl/cmd/diff_cmd.go

@@ -13,6 +13,7 @@ var (
 	diffFilename string
 	diffDebug    bool
 	diffContext  int
+	diffColor    string
 )
 
 // diffCmd represents the diff command
@@ -40,14 +41,18 @@ func init() {
 
 	// Flags and configuration settings
 	diffCmd.PersistentFlags().StringVarP(&diffFilename, "filename", "f", "", "configuration file")
-	diffCmd.PersistentFlags().BoolVarP(&diffDebug, "debug", "", false, "print extra debugging information")
-	diffCmd.PersistentFlags().IntVarP(&diffContext, "context", "", papply.DefaultContextLines, "number of lines of filter diff context to show")
+	diffCmd.PersistentFlags().BoolVar(&diffDebug, "debug", false, "print extra debugging information")
+	diffCmd.PersistentFlags().IntVar(&diffContext, "context", papply.DefaultContextLines, "number of lines of filter diff context to show")
+	diffCmd.PersistentFlags().StringVar(&diffColor, "color", "auto", "whether to enable color output (must be \"auto\" or \"never\")")
 }
 
 func diff(path string) error {
 	if diffContext < 0 {
 		return errors.New("--context must be non-negative")
 	}
+	if diffColor != "auto" && diffColor != "never" {
+		return errors.New("--color must be \"auto\" or \"never\"")
+	}
 
 	parseRes, err := parseConfig(path, "", false)
 	if err != nil {
@@ -64,7 +69,7 @@ func diff(path string) error {
 		return err
 	}
 
-	diff, err := papply.Diff(parseRes.Res.GmailConfig, upstream, diffDebug, diffContext)
+	diff, err := papply.Diff(parseRes.Res.GmailConfig, upstream, diffDebug, diffContext, diffColor == "auto")
 	if err != nil {
 		return fmt.Errorf("cannot compare upstream with local config: %w", err)
 	}

cmd/gmailctl/cmd/edit_cmd.go

@@ -21,6 +21,7 @@ var (
 	editSkipTests   bool
 	editDebug       bool
 	editDiffContext int
+	editColor       string
 )
 
 var (
@@ -70,14 +71,18 @@ func init() {
 	// Flags and configuration settings
 	editCmd.PersistentFlags().StringVarP(&editFilename, "filename", "f", "", "configuration file")
 	editCmd.Flags().BoolVarP(&editSkipTests, "yolo", "", false, "skip configuration tests")
-	editCmd.PersistentFlags().BoolVarP(&editDebug, "debug", "", false, "print extra debugging information")
-	editCmd.PersistentFlags().IntVarP(&editDiffContext, "diff-context", "", papply.DefaultContextLines, "number of lines of filter diff context to show")
+	editCmd.PersistentFlags().BoolVar(&editDebug, "debug", false, "print extra debugging information")
+	editCmd.PersistentFlags().IntVar(&editDiffContext, "diff-context", papply.DefaultContextLines, "number of lines of filter diff context to show")
+	editCmd.PersistentFlags().StringVar(&editColor, "color", "auto", "whether to enable color output (must be \"auto\" or \"never\")")
 }
 
 func edit(path string, test bool) error {
 	if editDiffContext < 0 {
 		return errors.New("--diff-context must be non-negative")
 	}
+	if editColor != "auto" && editColor != "never" {
+		return errors.New("--color must be \"auto\" or \"never\"")
+	}
 
 	// First make sure that Gmail can be contacted, so that we don't
 	// waste the user's time editing a config file that cannot be
@@ -229,7 +234,7 @@ func applyEdited(path, originalPath string, test bool, gmailapi *api.GmailAPI) e
 		return err
 	}
 
-	diff, err := papply.Diff(parseRes.Res.GmailConfig, upstream, editDebug, editDiffContext)
+	diff, err := papply.Diff(parseRes.Res.GmailConfig, upstream, editDebug, editDiffContext, editColor == "auto")
 	if err != nil {
 		return errors.New("comparing upstream with local config")
 	}

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/google/go-jsonnet v0.20.0
 	github.com/gorilla/mux v1.8.1
 	github.com/hashicorp/go-multierror v1.1.1
-	github.com/pmezard/go-difflib v1.0.0
+	github.com/martinohmann/go-difflib v1.1.0
 	github.com/spf13/cobra v1.9.1
 	github.com/stretchr/testify v1.10.0
 	golang.org/x/oauth2 v0.30.0
@@ -21,6 +21,7 @@ require (
 	cloud.google.com/go/auth/oauth2adapt v0.2.8 // indirect
 	cloud.google.com/go/compute/metadata v0.6.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/fatih/color v1.12.0 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/go-logr/logr v1.4.2 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
@@ -30,6 +31,9 @@ require (
 	github.com/googleapis/gax-go/v2 v2.14.1 // indirect
 	github.com/hashicorp/errwrap v1.1.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/mattn/go-colorable v0.1.8 // indirect
+	github.com/mattn/go-isatty v0.0.12 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/spf13/pflag v1.0.6 // indirect
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.60.0 // indirect

go.sum

@@ -7,6 +7,9 @@ cloud.google.com/go/compute/metadata v0.6.0/go.mod h1:FjyFAW1MW0C203CEOMDTu3Dk1F
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
+github.com/fatih/color v1.12.0 h1:mRhaKNwANqRgUBGKmnI5ZxEk7QXmjQeCcuYFMX2bfcc=
+github.com/fatih/color v1.12.0/go.mod h1:ELkj/draVOlAH/xkhN6mQ50Qd0MPOk5AAr3maGEBuJM=
 github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
@@ -21,6 +24,7 @@ github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/google/go-jsonnet v0.20.0 h1:WG4TTSARuV7bSm4PMB4ohjxe33IHT5WVTrJSU33uT4g=
 github.com/google/go-jsonnet v0.20.0/go.mod h1:VbgWF9JX7ztlv770x/TolZNGGFfiHEVx9G6ca2eUmeA=
+github.com/google/pprof v0.0.0-20190404155422-f8f10df84213/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
 github.com/google/s2a-go v0.1.9 h1:LGD7gtMgezd8a/Xak7mEWL0PjoTQFvpRudN895yqKW0=
 github.com/google/s2a-go v0.1.9/go.mod h1:YA0Ei2ZQL3acow2O62kdp9UlnvMmU7kA6Eutn0dXayM=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
@@ -42,6 +46,15 @@ github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/martinohmann/go-difflib v1.1.0 h1:cWipyTDwXGZeN/J0D1PbkupyMvOnqTrKRSMZ68y8Rbc=
+github.com/martinohmann/go-difflib v1.1.0/go.mod h1:AcMcOkYMsAiB5qTRFy5lmqgbGkN4IOEGuuo3zNXQp/A=
+github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
+github.com/mattn/go-colorable v0.1.8 h1:c1ghPdyEDarC70ftn0y+A/Ee++9zz8ljHG1b13eJ0s8=
+github.com/mattn/go-colorable v0.1.8/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
+github.com/mattn/go-isatty v0.0.5/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
+github.com/mattn/go-isatty v0.0.7/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
+github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
+github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
@@ -69,18 +82,27 @@ go.opentelemetry.io/otel/sdk/metric v1.35.0 h1:1RriWBmCKgkeHEhM7a2uMjMUfP7MsOF5J
 go.opentelemetry.io/otel/sdk/metric v1.35.0/go.mod h1:is6XYCUMpcKi+ZsOvfluY5YstFnhW0BidkR+gL+qN+w=
 go.opentelemetry.io/otel/trace v1.35.0 h1:dPpEfJu1sDIqruz7BHFG3c7528f6ddfSWfFDVt/xgMs=
 go.opentelemetry.io/otel/trace v1.35.0/go.mod h1:WUk7DtFp1Aw2MkvqGdwiXYDZZNvA/1J8o6xRXLrIkyc=
+golang.org/x/arch v0.0.0-20190312162104-788fe5ffcd8c/go.mod h1:flIaEI6LNU6xOCD5PaJvn9wGP0agmIOqjrtsKGRguv4=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.37.0 h1:kJNSjF/Xp7kU0iB2Z+9viTPMW4EqqsrywMXLJOOsXSE=
 golang.org/x/crypto v0.37.0/go.mod h1:vg+k43peMZ0pUMhYmVAWysMK35e6ioLh3wB8ZCAfbVc=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.39.0 h1:ZCu7HMWDxpXpaiKdhzIfaltL9Lp31x/3fCP11bc6/fY=
 golang.org/x/net v0.39.0/go.mod h1:X7NRbYVEA+ewNkCNyJ513WmMdQ3BineSwVtN2zD/d+E=
 golang.org/x/oauth2 v0.30.0 h1:dnDm7JmhM45NNpd8FDDeLhK6FwqbOf4MLCM9zb1BOHI=
 golang.org/x/oauth2 v0.30.0/go.mod h1:B++QgG3ZKulg6sRPGD/mqlHQs5rB3Ml9erfeDY7xKlU=
 golang.org/x/sync v0.14.0 h1:woo0S4Yywslg6hp4eUFjTVOyKt0RookbpAHG4c1HmhQ=
 golang.org/x/sync v0.14.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.32.0 h1:s77OFDvIQeibCmezSnk/q6iAfkdiQaJi4VzroCFrN20=
 golang.org/x/sys v0.32.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.24.0 h1:dd5Bzh4yt5KYA8f9CJHCP4FB4D51c2c6JvN37xJJkJ0=
 golang.org/x/text v0.24.0/go.mod h1:L8rBsPeo2pSS+xqN0d5u2ikmjtmoJbDBT1b7nHvFCdU=
+golang.org/x/tools v0.0.0-20190422165002-7f54bd5c703d/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 google.golang.org/api v0.232.0 h1:qGnmaIMf7KcuwHOlF3mERVzChloDYwRfOJOrHt8YC3I=
 google.golang.org/api v0.232.0/go.mod h1:p9QCfBWZk1IJETUdbTKloR5ToFdKbYh2fkjsUL6vNoY=
 google.golang.org/genproto/googleapis/api v0.0.0-20250218202821-56aae31c358a h1:nwKuGPlUAt+aR+pcrkfFRrTU1BVrSmYyYMxYbUIVHr0=
@@ -96,5 +118,6 @@ gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntN
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+rsc.io/pdf v0.1.1/go.mod h1:n8OzWcQ6Sp37PL01nO98y4iUCRdTGarVfzxY20ICaU4=
 sigs.k8s.io/yaml v1.4.0 h1:Mk1wCc2gy/F0THH0TAp1QYyJNzRm2KCLy3o5ASXVI5E=
 sigs.k8s.io/yaml v1.4.0/go.mod h1:Ejl7/uTz7PSA4eKMyQCUTnhZYNmLIl+5c2lQPGR2BPY=

internal/engine/apply/apply.go

@@ -116,20 +116,20 @@ func (d ConfigDiff) Validate() error {
 }
 
 // Diff computes the diff between local and upstream configuration.
-func Diff(local, upstream GmailConfig, debugInfo bool, contextLines int) (ConfigDiff, error) {
+func Diff(local, upstream GmailConfig, debugInfo bool, contextLines int, allowColor bool) (ConfigDiff, error) {
 	res := ConfigDiff{
 		LocalConfig: local,
 	}
 	var err error
 
-	res.FiltersDiff, err = filter.Diff(upstream.Filters, local.Filters, debugInfo, contextLines)
+	res.FiltersDiff, err = filter.Diff(upstream.Filters, local.Filters, debugInfo, contextLines, allowColor)
 	if err != nil {
 		return res, fmt.Errorf("cannot compute filters diff: %w", err)
 	}
 
 	if len(local.Labels) > 0 {
 		// LabelsDiff management opted-in
-		res.LabelsDiff, err = label.Diff(upstream.Labels, local.Labels)
+		res.LabelsDiff, err = label.Diff(upstream.Labels, local.Labels, allowColor)
 		if err != nil {
 			return res, fmt.Errorf("cannot compute labels diff: %w", err)
 		}

internal/engine/cfgtest/cfgtest.go

@@ -7,7 +7,7 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/pmezard/go-difflib/difflib"
+	"github.com/martinohmann/go-difflib/difflib"
 
 	"github.com/mbrt/gmailctl/internal/engine/config/v1alpha3"
 	"github.com/mbrt/gmailctl/internal/engine/gmail"

internal/engine/filter/diff.go

@@ -6,20 +6,20 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/pmezard/go-difflib/difflib"
+	"github.com/martinohmann/go-difflib/difflib"
 
 	"github.com/mbrt/gmailctl/internal/graph"
 )
 
 // Diff computes the diff between two lists of filters.
 //
 // To compute the diff, IDs are ignored, only the contents of the filters are actually considered.
-func Diff(upstream, local Filters, debugInfo bool, contextLines int) (FiltersDiff, error) {
+func Diff(upstream, local Filters, debugInfo bool, contextLines int, allowColor bool) (FiltersDiff, error) {
 	// Computing the diff is very expensive, so we have to minimize the number of filters
 	// we have to analyze. To do so, we get rid of the filters that are exactly the same,
 	// by hashing them.
 	added, removed := changedFilters(upstream, local)
-	return NewMinimalFiltersDiff(added, removed, debugInfo, contextLines), nil
+	return NewMinimalFiltersDiff(added, removed, debugInfo, contextLines, allowColor), nil
 }
 
 // NewMinimalFiltersDiff creates a new FiltersDiff with reordered filters, where
@@ -28,11 +28,11 @@ func Diff(upstream, local Filters, debugInfo bool, contextLines int) (FiltersDif
 // The algorithm used is a quadratic approximation to the otherwise NP-complete
 // travel salesman problem. Hopefully the number of filters is low enough to
 // make this not too slow and the approximation not too bad.
-func NewMinimalFiltersDiff(added, removed Filters, printDebugInfo bool, contextLines int) FiltersDiff {
+func NewMinimalFiltersDiff(added, removed Filters, printDebugInfo bool, contextLines int, allowColor bool) FiltersDiff {
 	if len(added) > 0 && len(removed) > 0 {
 		added, removed = reorderWithHungarian(added, removed)
 	}
-	return FiltersDiff{added, removed, printDebugInfo, contextLines}
+	return FiltersDiff{added, removed, printDebugInfo, contextLines, allowColor}
 }
 
 // FiltersDiff contains filters that have been added and removed locally with respect to upstream.
@@ -41,6 +41,7 @@ type FiltersDiff struct {
 	Removed        Filters
 	PrintDebugInfo bool
 	ContextLines   int
+	AllowColor     bool
 }
 
 // Empty returns true if the diff is empty.
@@ -64,6 +65,7 @@ func (f FiltersDiff) String() string {
 		FromFile: "Current",
 		ToFile:   "TO BE APPLIED",
 		Context:  f.ContextLines,
+		Color:    f.AllowColor,
 	})
 	if err != nil {
 		// We can't get a diff apparently, let's make something up here

internal/engine/label/diff.go

@@ -5,7 +5,7 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/pmezard/go-difflib/difflib"
+	"github.com/martinohmann/go-difflib/difflib"
 
 	"github.com/mbrt/gmailctl/internal/engine/filter"
 )
@@ -14,11 +14,11 @@ import (
 //
 // To compute the diff, IDs are ignored, only the properties of the labels are
 // actually considered.
-func Diff(upstream, local Labels) (LabelsDiff, error) {
+func Diff(upstream, local Labels, allowColor bool) (LabelsDiff, error) {
 	sort.Sort(byName(upstream))
 	sort.Sort(byName(local))
 
-	res := LabelsDiff{}
+	res := LabelsDiff{AllowColor: allowColor}
 	i, j := 0, 0
 
 	for i < len(upstream) && j < len(local) {
@@ -63,9 +63,10 @@ func Diff(upstream, local Labels) (LabelsDiff, error) {
 
 // LabelsDiff contains the diff of two lists of labels.
 type LabelsDiff struct {
-	Modified []ModifiedLabel
-	Added    Labels
-	Removed  Labels
+	Modified   []ModifiedLabel
+	Added      Labels
+	Removed    Labels
+	AllowColor bool
 }
 
 // Empty returns true if the diff is empty.
@@ -103,6 +104,7 @@ func (d LabelsDiff) String() string {
 		FromFile: "Current",
 		ToFile:   "TO BE APPLIED",
 		Context:  3,
+		Color:    d.AllowColor,
 	})
 	if err != nil {
 		// We can't get a diff apparently, let's make something up here