A sample DragonRuby program to display a few learnings; How to include new classes, create buttons to update state, manage the update loop, and easily add new color schemes.

color_palatte.rb

class ColorPalatte
    attr_accessor :colors
  
    def initialize clrs
      clrs.each_with_index do |c, i|
        clrs[i] = hex_to_rgb c
      end
      @colors = clrs
    end
  
    def get_color n
      return @colors[n]
    end
  
    def get_colors
      @colors
    end
  
    def hex_to_rgb hex
      r = hex[0..1].hex
      g = hex[2..3].hex
      b = hex[4..5].hex
      [r,g,b]
    end
  
  end

# As seen on http://clrs.cc/css/colors.css

$AQUA  = '7FDBFF'
$BLUE  = '0074D9'
$NAVY  = '001F3F'
$GREEN = '2ECC40'
$TEAL  = '39CCCC'
$OLIVE = '3D9970'
$LIME  = '01FF70'

$MAROON = '85144B'
$PURPLE = 'B10DC9'
$RED    = 'FF4136'
$YELLOW = 'FFDC00'
$FUCHSIA= 'F012BE'

$SILVER = 'DDDDDD'
$GRAY   = '444444'
$BLACK  = '111111'
$WHITE  = 'FFFFFF'

$grayscale = [$BLACK, $GRAY, $SILVER, $WHITE]
$megaman   = [$NAVY, $BLUE, $AQUA, $SILVER]
$bright    = [$RED, $LIME, $TEAL, $YELLOW]
$red_n_blue= [$RED, $MAROON, $BLUE, $NAVY]
$reds      = [$MAROON, $PURPLE, $RED, $YELLOW, $FUCHSIA]

# Other potential palattes on https://lospec.com/palette-list

main.rb

$dragon.require('app/color_palatte.rb')

class PalatteExample
  attr_accessor :grid, :inputs, :game, :outputs, :dragon

  def tick
    defaults
    render
    # comment next line to stop the colors cycling every n seconds
    updates 4
    input_mouse
  end

  def render
    # Todo: Center the buttons and colors, especially as more get added. (Maybe even a second row)
    
    game.palatte = game.palattes[game.loaded_pallate]

    game.palatte.get_colors.each_with_index do |c, i|
      outputs.solids << [grid.w * 0.405 + 60*i, 300, 50, 50, c ]
    end

    outputs.labels << [ grid.w * 0.5, 600, "Color scheme loaded: #{game.loaded_pallate}", 0, 1 ]
    outputs.labels << [ grid.w * 0.5, 550, "First color: #{game.palatte.get_color(0)}", 0, 1]
    outputs.labels << [ grid.w * 0.5, 500, "Keys: #{game.palattes.keys.map { |e| e.to_s.capitalize }}", 0, 1]

    game.palattes.keys.each_with_index do |p, i|
      game.palatte_buttons[i] ||= palatte_button(p, i + 1)
      outputs.labels  <<  game.palatte_buttons[i].label
      outputs.borders <<  game.palatte_buttons[i].border
    end
  end

  def input_mouse
    return unless inputs.mouse.click

    button_clicked = outputs.borders.find_all do |b|
      inputs.mouse.click.point.inside_rect? b
    end.reject {|b| !game.meta(b)}.first

    return unless button_clicked

    label_clicked = game.meta(button_clicked)
    if game.palattes.keys.include? label_clicked
      game.loaded_pallate = label_clicked
    end
  end

  def palatte_button name, position
    game.new_entity(:button) do |b|
      # Labels  (x, y, text, size, align, r, g, b, a)
      b.label  =  [grid.w * 0.30 + 105.mult(position), grid.h * 0.6, "#{name.capitalize}", 0, 1, 0, 0, 0]
      # Borders (x, y, w, h, r, g, b, a)
      b.border =  game.with_meta([grid.w * 0.30 + 105.mult(position) - 50, grid.h * 0.6 - 32, 100, 50], name)
    end
  end

  def updates n
    if (game.tick_count % (n*60)) == 0 
      a = game.palattes.keys
      l = game.loaded_pallate
      game.loaded_pallate = a[a.find_index(l) + 1] || a[0]
    end
  end

  def defaults
    # Create the array of colors in app/color_palatte.rb, then include it here
    game.palattes ||= {
      grayscale: ColorPalatte.new($grayscale),
      megaman: ColorPalatte.new($megaman),
      bright: ColorPalatte.new($bright),
      red_n_blue: ColorPalatte.new($red_n_blue),
      reds: ColorPalatte.new($reds)
    }
    game.loaded_pallate ||= :megaman
    game.palatte_buttons ||= []
  end

end

$palatte_example = PalatteExample.new

def tick args
  $palatte_example.grid = args.grid
  $palatte_example.inputs = args.inputs
  $palatte_example.game = args.game
  $palatte_example.outputs = args.outputs
  $palatte_example.dragon = args.dragon
  $palatte_example.tick
end

Sample image as of Revision 1 -