Roy Osborne is an artist, author and educator who has sustained interest in all aspects of colour since studying art and design at Brighton Polytechnic. In various ongoing series of paintings he has explored colour theory, colour harmony, contour, optical colour mixing, and illusory depth in works that typically integrate figure-ground ambiguity, regular patterns, formal symmetry and hard-edge versus soft-edge, often with illusions of transparency or light-and-shade. His abstracts generally feature horizontal, vertical, diagonal or curved divisions of a square. Regular patterns encourage the eye to explore arrays of colours, with rhythm provided by simple formal divisions and prominent colour contrasts or groupings. A presentation of his theories is included in Color Influencing Form (2004).