I'm generally acknowledged to be the style expert here.
My rule is...dont clash...
Thus when I am wearing black knee socks and black penny loafers with plaid shorts (blue or red) I choose a black holster.
When I am wearing a white fundoshi, white platform flip fops and a white halter, I again, chose black as my accessory.
Patterned thongs are tough. I have a Hello Kitty one which is red and black, so again, I generally seek black holsters especially when wearing the latex thigh highs which match my thong.
Those are my more formal looks. With denim daisy duke shorts and a white midriff blouse, I choose brown.
WildletmedressyouAlaska ™