Color Modes

Three Modes

output.ColorModeAuto    // Detects TTY, respects NO_COLOR / CI / FORCE_COLOR
output.ColorModeAlways  // Always emit ANSI colors
output.ColorModeNever   // Never emit ANSI colors

Wiring Mechanisms

Different renderers accept color mode through different APIs:

Functional option (terminal tables)

tbl := table.New(table.WithColorMode(output.ColorModeAlways))

Setter (ASCII tree, markdown)

renderer := tree.NewASCIITreeRenderer()
renderer.SetColorMode(output.ColorModeAlways)

md := markdown.NewMarkdownTable().SetColorMode(output.ColorModeAlways)

RenderOptions (unified dispatch)

out, _ := output.RenderTable(data, output.FormatTable, output.RenderOptions{
    ColorMode: output.ColorModeAuto,
})

Auto Detection

ColorModeAuto checks (in order):

1. Writer TTY — Probes the writer’s own FD via x/term.IsTerminal
2. NO_COLOR — If set, disables color (industry standard)
3. CI environments — CI, GITHUB_ACTIONS, GITLAB_CI, JENKINS_URL, BUILDKITE
4. GO_OUTPUT_FORCE_COLOR / FORCE_COLOR — If set, forces color on

The only valid direction is TTY to plain text — a piped writer never gets ANSI codes.