Colorful Test Output
The standard command line use when testing go:
$ go test
Colors your test output according to your terminal configuration.
@rakyll has implemented a cool tool gotest for coloring your test output, so you have passing tests colored green, failing tests marked red etc.
$ gotest
You can customize the colors for failing tests and passing tests via environment variables using the palette of your terminal.
GOTEST_PALETTE="red,green" gotest
The first color being for failures and the second one being for passes.
To find the colors in for example iTerm.app open the Preferences, your profile and the color tab.
Use the names for the colors in the environment variables
And interesting alternative is richgo which has even more options (see: Enriched Test Output).