replace #FAABAE colors in css with hsl(1,2,3) style, and invert lightness while doing that

Hex2InvertedHSL.rb

require "color"; 

class Hex2InvertedHSL
  def initialize;  @convs={}; end;

  def do(line)
    line.gsub(/#[0-9a-fA-F]{6}/) { |hex|
      @convs[hex] || (@convs[hex]=conv(hex))
    }
  end
  
  def hex2hsl(hex)
    _, *hex = hex.unpack("A1A2A2A2");
    Color::RGB.new(*(hex.map { |val| val.to_i(16) })).to_hsl;
  end

  def conv(hex)
    hsl=hex2hsl(hex)
    hsl.l=1.0-hsl.l; # invert lightness
    hsl.css_hsl;
  end
end

h2hsl = Hex2InvertedHSL.new

while(gets)
  puts h2hsl.do($_)
end