Student or Learner
Which of these sentences is/are common?
1. Such objects are perfectly color-coded.
2. Such objects are perfectly color-organized.
3. Such objects are perfectly color-collected.
( If we want to say those objects are organized according to color, usually to make something easier!)
Coded definition in Longman:
Having a set of numbers, letters, or symbols to show what sth is or give information about it.
EX: The wires are colour-coded for easy identification.
As you say, 1 and 2 might be used. However, I haven't seen such a combination: color-organized. Is it the same as color-coded?
Or "arranged by colour". If you want to use "colour" followed by a hyphen and another word, I find only "colour-coded" natural (of your three suggestions).
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
Color-coded works, but it doesn't necessarily mean that they are organised. I think emsr2d2's suggestion does that better.