It offers 2 modes. The HSV system is the one used by Scratch. Look under to see which convertor it offers. Mode 0 : You can change substractive color to see which color correspond (drawn) and its code in RGB, Hexadecimal, HSV. Mode 1 : You can change HSV values (Hue, Saturation and Value) and get the corresponding RGB, Hex and Substractive code. How does it work ? Mode 0 : Substractive colors are converted into RGB, which is then converted in Hex and HSV. So : Sub => RGB => (HSV and Hex) Mode 1 : HSV turn into RGB, RGB converted in subsrative system and Hex So : HSV => RGB => (Sub and Hex) This project contains these following convertors : - Substractive to RGB - RGB to Substractive - RGB to Hexadecimal - Hexadecimal to RGB - RGB to HSV - HSV to RGB