Here's a sample of colour palettes from some of the visual precedents I've been looking at, ranging between TV programmes and popular breakfast cereals. A lot of brightly hued primary colours, with some browns and black for contrast.

The last image is a possible palette - the traffic light / vegetable colour scheme on white / sky blue. That could work - will be updated after my first round of focus group research with my respondents (HEC application already in as of 11.09, finally - means I can be in business as early as 06.10)