Terminal Color

A lightweight Go package for colorful and styled terminal output with ANSI escape sequences support.

Features

• Support for all 16 basic ANSI colors (8 normal + 8 bright) for foreground and background
• Text styling: bold, italic, underline, dim
• Automatic terminal capability detection
• Environment variable support (NO_COLOR, FORCE_COLOR)
• Thread-safe operations with optimized caching
• Cross-platform compatibility (Unix/Linux/macOS, Windows 10+)
• Zero dependencies

Installation

go get github.com/haadi-coder/color

Usage

Basic Usage

package main

import (
    "fmt"
    "github.com/haadi-coder/color"
)

func main() {
    fmt.Println(color.Red("Error: file not found"))
    fmt.Println(color.Green("Success: operation completed"))
    fmt.Println(color.Yellow("Warning: deprecated method"))
    fmt.Println(color.Blue("Info: processed 100 files"))
}

Advanced Usage

// Combining multiple styles
fmt.Println(color.Style("Critical Error", color.AttrFgRed, color.AttrBold, color.AttrUnderline))

// Background colors
fmt.Println(color.Style("Alert", color.AttrFgWhite, color.AttrBgRed, color.AttrBold))

// Bright colors
fmt.Println(color.BrightGreen("Tests Passed"))
fmt.Println(color.BrightRed("Critical Issue"))

// Formatted output
fmt.Println(color.Redf("Error: %s", err.Error()))
fmt.Println(color.Greenf("Processed %d of %d files", processed, total))

Environment Control

// Global color control
color.NoColor = true    // Disable all colors
color.ForceColor = true // Force colors even in non-TTY

// Check terminal capabilities
if color.IsTerminal() && color.SupportsColor() {
    fmt.Println(color.Green("Terminal supports colors"))
} else {
    fmt.Println("Plain text output")
}

API

Basic Color Functions

• Red(text string) string - Red text
• Green(text string) string - Green text
• Yellow(text string) string - Yellow text
• Blue(text string) string - Blue text
• Magenta(text string) string - Magenta text
• Cyan(text string) string - Cyan text
• White(text string) string - White text
• Black(text string) string - Black text

Bright Color Functions

• BrightRed(text string) string - Bright red text
• BrightGreen(text string) string - Bright green text
• BrightYellow(text string) string - Bright yellow text
• BrightBlue(text string) string - Bright blue text
• BrightMagenta(text string) string - Bright magenta text
• BrightCyan(text string) string - Bright cyan text
• BrightWhite(text string) string - Bright white text
• BrightBlack(text string) string - Bright black text

Background Color Functions

• BgRed(text string) string - Red background
• BgGreen(text string) string - Green background
• BgYellow(text string) string - Yellow background
• BgBlue(text string) string - Blue background
• BgMagenta(text string) string - Magenta background
• BgCyan(text string) string - Cyan background
• BgWhite(text string) string - White background
• BgBlack(text string) string - Black background

Bright Background Color Functions

• BgBrightRed(text string) string - Bright red background
• BgBrightGreen(text string) string - Bright green background
• BgBrightYellow(text string) string - Bright yellow background
• BgBrightBlue(text string) string - Bright blue background
• BgBrightMagenta(text string) string - Bright magenta background
• BgBrightCyan(text string) string - Bright cyan background
• BgBrightWhite(text string) string - Bright white background
• BgBrightBlack(text string) string - Bright black background

Text Style Functions

• Bold(text string) string - Bold text
• Italic(text string) string - Italic text
• Underline(text string) string - Underlined text
• Dim(text string) string - Dimmed text

Formatted Functions

• Redf(format string, a ...interface{}) string - Red formatted text
• Greenf(format string, a ...interface{}) string - Green formatted text
• Yellowf(format string, a ...interface{}) string - Yellow formatted text
• Bluef(format string, a ...interface{}) string - Blue formatted text
• Magentaf(format string, a ...interface{}) string - Magenta formatted text
• Cyanf(format string, a ...interface{}) string - Cyan formatted text
• Whitef(format string, a ...interface{}) string - White formatted text
• Blackf(format string, a ...interface{}) string - Black formatted text

Advanced Functions

• Style(text string, attrs ...Attr) string - Apply multiple attributes
• IsTerminal() bool - Check if output is connected to terminal
• SupportsColor() bool - Check if terminal supports colors

Attributes

type Attr int

const (
    // Foreground colors
    AttrFgBlack, AttrFgRed, AttrFgGreen, AttrFgYellow,
    AttrFgBlue, AttrFgMagenta, AttrFgCyan, AttrFgWhite,
    
    // Bright foreground colors
    AttrFgBrightBlack, AttrFgBrightRed, AttrFgBrightGreen, AttrFgBrightYellow,
    AttrFgBrightBlue, AttrFgBrightMagenta, AttrFgBrightCyan, AttrFgBrightWhite,
    
    // Background colors
    AttrBgBlack, AttrBgRed, AttrBgGreen, AttrBgYellow,
    AttrBgBlue, AttrBgMagenta, AttrBgCyan, AttrBgWhite,
    
    // Bright background colors
    AttrBgBrightBlack, AttrBgBrightRed, AttrBgBrightGreen, AttrBgBrightYellow,
    AttrBgBrightBlue, AttrBgBrightMagenta, AttrBgBrightCyan, AttrBgBrightWhite,
    
    // Text styles
    AttrBold, AttrItalic, AttrUnderline, AttrDim
)

Global Variables

• NoColor bool - Disable all colors (also controlled by NO_COLOR env var)
• ForceColor bool - Force colors even in non-TTY (also controlled by FORCE_COLOR env var)

Environment Variables

• NO_COLOR=1 - Disable all colors (follows no-color.org standard)
• FORCE_COLOR=1 - Force colors even when not in terminal
• TERM=dumb - Automatically disables colors
• COLORTERM=truecolor - Enables color support

Platform Support

• Unix/Linux/macOS: Full support out of the box
• Windows 10+: Full support with modern terminals
• Windows Terminal: Full support
• Git Bash: Full support
• WSL: Full support as Unix environment
• Older Windows: Colors automatically disabled, use FORCE_COLOR=1 if needed

Performance

• ANSI sequences are pre-computed and cached
• Thread-safe operations with optimized locking
• Minimal memory allocations for typical usage
• Efficient string building with strings.Builder