MiniMagick & ImageMagick - Level Colors and Composite

image.rb

require 'rubygems'
require 'mini_magick'

color = '#103afc'

img = MiniMagick::Image.open("letter_x.png")

img.combine_options do |c|
  c.add_command( 'level-colors')
  c.+ "#{color},"
end
img.write("output1.png")

com = MiniMagick::Image.open('fruits.png')

com.combine_options do |c|
  c.add_command( 'level-colors')
  c.+ "white,#{color}" 
end

result = img.composite(com) do |c|
  c.geometry '-0-10'
  c.gravity 'North'
end
result.write("output.png")