The first time I saw this was on a first generation RP, and they weren't color coded at that time.
While I find color coding really useful for cams, I've always done alright with visually matching nuts to the placement, so the color coding nuts doesn't do much for me. My rack is a motley assortment of things, very few factory slings on cams, it's like speaking a private language. Consequently, I find leading with someone else's rack is more challenging than working with my familar tools.