Most of the main characters from Peter's Angel have colors which embody their essence in a deep way. Very few of my other characters have such meaningful color associations, however. This may be simply because the PA characters are the most developed of my creations, but it might also be because of how my PA characters came to be.
As some of you know, Peter's Angel actually developed from a fanfic I'd written for LEGO Exo-Force. The "ancestors" of my characters were all anime figures with wacky colors of hair. Naturally those colors came to embody the essence of the character, so when I decided to rewrite the story as fantasy with normal-looking people, those colors transferred to other elements of the character's appearance and still remain a strong symbol of the character's personality. Through all the revisions, all the changes, the core essence has remained the same, and the color still lingers, cropping up in the character's looks and wardrobe.
Peter's predecessor had ice blue hair, representative of his chill, authoritative personality, which Peter still has. Peter's eyes have always been blue, and I have always envisioned him wearing robin's egg and slate blue. Is it any surprise that he morphed into a patriot soldier with a blue uniform?
Edwin's predecessor had green hair, and again, his green eyes have always been a notable part of his appearance. Red hair is a nice compliment to that, so he morphed into an Irishman, husky, strong, and kind, but also fiery and headstrong.
Nathan's predecessor had purple hair, and I still see purple as suitable for Nathan because of his noble character and royal heritage. He has a kingly bearing to him even if he doesn't realize it, and one day he will assume the role of authority that is rightfully his. (Oops! Guess that was a spoiler.

) Purple is rich and kingly but also in a kind way. Again, noble. Pure of heart. However, I couldn't very well give the kid purple eyes, so he came to have brown hair and brown eyes because brown represents the other part of him. The soft, gentle, unassuming part. The part that is weak, tender, and afraid. The part that wants nothing to do with the kingly, authoritative, royal side of him.
In a slightly lesser way, I've always envisioned Mariah as a contrast of black (dark hair, dark clothes) and white (pale skin). I am not sure why, but she was practically goth in the first revision she showed up in. She's still a bit of a rebel, and I cannot envision her wearing anything more bright or bold than burgundy or navy. I'm not entirely sure why, but it's part of her essence.
I don't think we need to "try" and convey these essences to our readers. Essence is intrinsic. It will emanate from the character itself. It is not something that needs to be told to the reader; it's something that helps we as the writers understand the character. The reader will figure it out for themselves.