add GINKGO_NO_COLOR to disable colors via environment variables

docs/index.md

@@ -3445,7 +3445,7 @@ When you [filter specs](#filtering-specs) using Ginkgo's various filtering mecha
 #### Other Settings
 Here are a grab bag of other settings:
 
-You can disable Ginkgo's color output by running `ginkgo --no-color`.
+You can disable Ginkgo's color output by running `ginkgo --no-color` or setting the `GINKGO_NO_COLOR=TRUE` environment variable.
 You can also output in a format that makes it easier to read in github actions console by running `ginkgo --github-output`.
 
 By default, Ginkgo only emits full stack traces when a spec panics.  When a normal assertion failure occurs, Ginkgo simply emits the line at which the failure occurred.  You can, instead, have Ginkgo always emit the full stack trace by running `ginkgo --trace`.

formatter/formatter.go

@@ -82,6 +82,10 @@ func New(colorMode ColorMode) Formatter {
 		return fmt.Sprintf("\x1b[38;5;%dm", colorCode)
 	}
 
+	if _, noColor := os.LookupEnv("GINKGO_NO_COLOR"); noColor {
+		colorMode = ColorModeNone
+	}
+
 	f := Formatter{
 		ColorMode: colorMode,
 		colors: map[string]string{

types/config.go

@@ -328,7 +328,7 @@ var ParallelConfigFlags = GinkgoFlags{
 // ReporterConfigFlags provides flags for the Ginkgo test process, and CLI
 var ReporterConfigFlags = GinkgoFlags{
 	{KeyPath: "R.NoColor", Name: "no-color", SectionKey: "output", DeprecatedName: "noColor", DeprecatedDocLink: "changed-command-line-flags",
-		Usage: "If set, suppress color output in default reporter."},
+		Usage: "If set, suppress color output in default reporter.  You can also set the environment variable GINKGO_NO_COLOR=TRUE"},
 	{KeyPath: "R.Verbose", Name: "v", SectionKey: "output",
 		Usage: "If set, emits more output including GinkgoWriter contents."},
 	{KeyPath: "R.VeryVerbose", Name: "vv", SectionKey: "output",