I'm a visual artist with a very strong sense of color. Sometimes I blanch when I see people wearing colors that look horrible on them. I'm olive-skinned brunette and here are my palette categories:

"oh-my-gosh-that-color-looks-gorgeous-on-you!" (me)
black, white, anything bright
all red derivatives -- red, orange, hot pink, fuchsia, bright purples
turquoise, the brighter the better
turquoise-green
sunshine yellow (bright yellow with hint of orange, not green-yellows)
bright peach or salmon
french vanilla or light pure (non-green) yellow

OK colors
darker cranberry or purples
red-browns, rust, and other non-green browns
light lime
bright purple-blue or green-blue
bubble gum pink

Kiss of Death
gray
khaki green
beige (not off-white, which I can wear)
mustard
navy blue
denim blue
baby blue
blue
pastel pink, lavendar, blue or green
acid yellow
did I mention navy blue? I really look putrid in that color.

As far as patterns -- I love anything animal print, although I have to be careful with certain browns or beige tones. I wear solid tops a lot with either solid or patterned bottoms, because jewelry doesn't go with patterned tops. I do like unusual big pattern tops, though. I never wear cute little florals.