Salmon's early work included the series "The Cybermen" for Doctor Who Magazine and "Judge Karyn" for the Judge Dredd Megazine. He then spent time working on various Panini Comics titles including The Rugrats and Action Man. Salmon later became better known as a comic book colourist, working primarily on the Doctor Who strip and various Panini superhero titles.
He was commissioned to work on the ongoing 'Time Team' series of articles for Doctor Who Magazine, providing illustrations of the televised Doctor Who stories. He also provides the cover artwork for the Bernice Summerfield range of audio CDs produced by Big Finish Productions.
Salmon has published a graphic novel, The Faceless: A Terry Sharp Story.