It just sounds like your skin is irritated and it shouldn't be an issue. Sweat build up and other factors can all cause discoloration, which could easily be what is going on since you are very active.
Thanks a lot for the reply! I am very active do a lot of sports it's just red painless Mark as such never caused any discomforts and never enlarged or anything is there any reason why it's been there for such a long time?
A rash-like appearance can be from many different things, anything from poor circulation to irritation to allergic reaction or something else. It's really hard to say what is going on. If it has been there for many years and causes no discomfort or problems, then it's most likely nothing to worry about. Though if you are worried about it, make a doctor's appointment to have it looked at to find out what is going on. Although depending on a number of factors the head of the penis can change in appearance of color. It's typically never a sign of anything really wrong and is commonly caused by irritation from being rubbed wrong or from sweat build up.