Teenagers usually aren't bothered by the look of metal braces – in fact, they often wear them as an accessory. The different colours of elastic ties are designed to motivate children to wear these appliances. Of course, aesthetic and even lingual braces can be fitted at any age, but since teenagers' oral hygiene often isn't good enough, any reduction in the time an orthodontic appliance has to be worn matters. That's why metal braces are preferable.
This answer is for general information. Your own case needs an examination by an orthodontist.