Around the top of my penis, the skin is ver dark (like a dirty colour) and its patchy and i think maybe is because of masturbation! is there anyway i ?

Not likely: So this failed soap&water? Is it a new change, or has it looked similar for years? The longer it's looked that way, the better, as is most likely normal for you. If new/changed, should be seen by a urologist to be sure is not a problem. Might be from your choice of lube and/or dirt/chemicals on hands--wash beforehand.

Penis color: Is possible to cause bleeding under the skin if you cause trauma during masturbation.