Generate a random hex color, or with fixing anyone color

random_color.rb

class RandomColor
  def self.get_random
    rand(255)
  end

  def self.color_hex(options = {})
    default = { red: get_random, green: get_random, blue: get_random }
    options = default.merge(options)
    '#%X%X%X' % options.values
  end
end

full random colour

RandomColor.color_hex() => #299D3D
RandomColor.color_hex() => #C0E92D

freeze any color

RandomColor.color_hex(red: 100) => #644BD6
RandomColor.color_hex(red: 100) => #6488D9