lately I have started using black and white, which makes the colored trend lines (of which my charts have many) easier to see. Red and Green candles make the colored trend lines harder to decipher.
" What color candles do you prefer" Green ones when I'm long and red ones when I'm short. I really really like those long candles too.
Black candles against a brown background. Easy on the eyes too. Black AND red can cause unnecessary bias - consciously or subconsciously.