Dark gums are very normal for black/brown and even light brown people - they can also be inherited through genes. If this is your case: Do not worry about it - unless your gum isn't soar - if it isn't, you should contact your dentist.

If it is a pigmentation issue and you are feeling uncomfortable with it, don't worry, it is treatable and it is a simple procedure that doesn't take much time: You should go to the dentist.