Poor Wandering One
Okay, now you two are just trying to make my head explode. It's like an information tsunami. I am overwhelmed, but I thank you both for pointing out some PDFs to download and links to bookmark.
Ultimately, you are right. A journey inward is always taken alone--and no matter what props I may have at my disposal (or how much they cost), they don't actually come with me. I'm of the mind that nothing has intrinsic value or meaning. Value and meaning is assigned by us.
The GD Tarot generally uses what's called the Queen Scale of coloring based on Tree of Life associations. 777 as mentioned earlier is the key to this system. See also: http://www.golden-dawn.org/generation-of-three-colour-wheels-of.html
The RWS deck uses the color associations to the planets, signs and elements a little more generally. Looking around the net I found this page which gives a publicly-palatable version of their color associations.
http://www.cosmictarot.co.uk/colour-symbolism/