colors.rb

#!/usr/bin/env ruby

lines = `git log -n 400 --format=oneline`.split("\n")
lines.map! do |line|
  sha, *msg = line.split
  msg = msg.join(' ') # unused
  colors = sha.scan(/[a-z0-9]{8}/)
  stops = colors.map do |color|
    rgba = color.scan(/[a-z0-9]{2}/).map {|o| o.to_i(16)}
    "rgba(#{rgba.join ','})"
  end
  style = "background-image: -webkit-linear-gradient(180deg, #{stops.join(',')})"
  %{<div class="box" style="#{style}"></div>}
end

File.open('colors.html', 'w') do |f|
  f.puts <<-HTML
  <style>
    body   { margin:0; padding:0; }
    .box   { width:100%; height:5px}
  </style>
  #{lines}
  HTML
end

shot.md