I am trying to write an extension in netlogo for Nxt brick . To connect the brick , I am using Lejos. I have a problem with color sensor. I want to write a simple method which returns sensor color as a number such as yellow : 1, red :2 etc. But sensor motor always returns different RGB colors on the same surface. For example I put it over a yellow paper , rgb colors are : [236 189 104] ,[247 202 108].. if it was returning unique RGB numbers for same surface colors, I would classify them according to RGB colors range and give a unique number for each color. Do you have any idea how i can do it ? Also , it won't run on different surfaces. only doing this for my paper colors( yellow, blue, green) will be enough for me. Thanks.