There are two types of colored contact lenses based on the prescription. One is with prescription which is suitable for those short sighted people. The other type is with no prescription which is just used to beautify the looks. You can choose this type. However, you should keep good hygiene habit of using contact lenses to avoid the eyes infection.
I think you need to go to visit an eye doctor first though you have perfect vision and only want to wear colored contacts, you can ask the doctor to determine which kind and type of contacts is the best suited ones for you. Because if the contacts are in the wrong size or type for you, they can cause irritation or scratch the lens of your eye.
There are a lot of market vendors and beauty supply shops which sell contacts with no prescriptions to those who have perfect visions. If you can buy the one with right type, it would not hurt your eyes.
Of course, you can wear colored contact lenses to enhance your beauty. Contact lenses have two main categories, which are cosmetic and non-cosmetic contact lenses. The non-cosmetic contact lenses have prescription that can correct eye vision, and the cosmetic contact lenses just used for decorating eyes. The colored contact lenses belong to the cosmetic type. However, you should not wear them for a prolonged period due to the color would direct contact your cornea that would be easy cause eye infection.