Pretty much anything you want really...... I never did A levels and Im a licensed engineer now. The best way if you want to go down the engineering route is an apprenticeship, Monarch, Virgin and Flybe all do them as well as others. This is considered by many to be the best route as you learn as you go along, gaining knowledge from engineers who have been there and done that.
100 times better than any of the colleges can develop you.
Then there is ops/crewing the list is endless, it depends where you want to go.....
(I dont know what your medical problem is but colour blindness could be a problem with engineering)