My penis skin & testicles for dark and even down its more as if black. no allergies and i do maintain hygiene. any tip or things on 'wikihow' any good?

Doctor can check: One can ask one's primary care doctor to look, if one is worried. A darker bottom penis and lighter top is normal if it looks symmetrical and has been that way since puberty started. Doctors check the penis at annual check-ups, but rarely say anything if such coloring is there, as it is considered normal. Lighter skin due to loss of color, or color changes due to inflammation, may need treatment.