Following up on Doranchak's (10) discussion of genetic programming and lace patterns: knitter Debbie New is one of many mathematically-inclined knitters using agent-based and cellular automata algorithms to generate patterns (which you can use for either color or texture). Here's some background on cellular automaton knitting:

http://www.knitting-and.com/knitting/tips/automaton.htm

Some of the coolest stich patterns I've come up with are due to this technique.