Term::Color

Powerful color utilities, truecolor strings, and terminal color capability detection for Crystal.

Term::Color combines two pieces:

• A rich color API (based on the former cor library) for creating, composing, and formatting colors (hex/rgb, math operations, string helpers).
• Terminal capability detection (from the original term-color) to determine supported color modes (8/16/52/64/256/24-bit) and general color support in the active terminal.

Installation

Add this to your application's shard.yml:

dependencies:
  term-color:
    github: crystal-term/color

Then run:

shards install

Usage

1. Creating Colors

require "term-color"

# Basic RGB
red = Term::Color.new(255, 0, 0)

# From hex
red = Term::Color.new("FF0000")

# Named color
red = Term::Color.color(:red)

# With alpha
mid_red = Term::Color.new(255, 0, 0, 128)

2. Formatting

blue = Term::Color.color(:blue)

# Hex
puts blue.hex_string            # => 0000ff
puts blue.hex_string(prefix: true)   # => #0000ff
puts blue.hex_string(alpha: true)    # => 0000ffff
puts blue.hex_string(upcase: true)   # => 0000FF

# RGB
magenta = Term::Color.color(:magenta)
puts magenta.rgb_string                 # => rgb(255, 0, 255)
puts magenta.rgb_string(alpha: true)    # => rgb(255, 0, 255, 1)

3. Math with Colors

puts Term::Color.color(:magenta) - Term::Color.color(:blue)
# => #<Term::Color ...>

4. Truecolor Strings (24-bit)

Most modern terminals support 24-bit color. Term::Color adds chainable String helpers.

require "term-color"
require "color/string"

puts "This is awesome!".fore(:blue).back(:white)
puts "Bold me!".bold
puts "Italic me!".italic
puts "Strike me!".strike
puts "Blink me like it's 1999!".blink
puts "Faint me!".faint
puts "Underline me!".underline
puts "Overline me!".overline

5. Terminal Color Capability Detection

Use the merged capabilities from the original term-color to determine mode and support.

require "term-color"

env = ENV.to_h

# Mode returns a color depth: 0, 8, 16, 52, 64, 256, or 2**24 (24-bit)
mode = Term::Color::Mode.new(env).mode
puts "Color mode: #{mode}"

# Support checks whether colors are supported in general
support = Term::Color::Support.new(env)
if support.disabled?
  puts "NO_COLOR set; colors disabled"
elsif support.support?
  puts "Terminal supports colors"
else
  puts "No color support detected"
end

Contributing

1. Fork it (https://github.com/crystal-term/color/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

License

MIT © Chris Watson