Simon's work has historically been associated with strong colours and the investigation of ‘edges’. Edges between representation and abstraction, and also the physical nature of edges of paint; whether hard or loose delineations or soft blending, each specifically chosen to better evoke moods and create visual effects. Simon's background has been in architecture and graphic design, and he has painted continuously as an integral activity to his professional commitments.

He now focuses much more deliberately and consistently on his artwork production. Simon displays within his paintings a form of controlled ambiguity, or a layered interplay structured to be evocative of feelings and memories – either related to a sense of place, or impressions derived from the interactions of colours themselves. While his focus has long been on semi-abstracted landscapes, more recently he has also been exploring pure abstraction and colour theory.