He was killed in practice for a hillclimb at Craigantlet, Northern Ireland, and is widely considered one of the best drivers never to have won the British Hill Climb Championship. His best year was 1994, when he was runner-up to David Grace. Outside motorsport, Colton was involved with home computers, and was the author of both the View range on the BBC Micro and PipeDream for the Cambridge Z88. Mark Colton was killed during his opening practice run at Craigantlet Hillclimb, Northern Ireland, when the front wing of his Pilbeam MP72-Judd failed and folded back under the car. He lost control and crashed into a telegraph pole head-on. Colton was the third driver to be killed in a British Hillclimb Championship event, after Bill Sleeman, killed at Bouley Bay in 1955 and Mike Gray who died at Barbon Manor in 1964. Colton's accident was the first fatal crash in a Northern Ireland hillclimb since Neville Johnson's accident happened at Spelga Dam in the early 70s.