Press 1 - 4 to see different polygon patterns. Press c to see the colours 0 - 100 (from left to right). Press b to change the background (black or squares). Use turbo (shift+green flag) for a quick look at the patterns, don´t use turbo if you want to see the process.
INCREASING OR DECREASING SIZE? The idea (left/right): Choose a pattern of polygons. Draw layer upon layer of the pattern changing the colour and increasing/decreasing the size of the pattern.