When we took our young daughter to Whitby, years ago (she is now a Mum) we bought her a colouring book of Morrismen to occupy her while we danced in the Playford workshops etc. It had various teams illustrated, and told you which colours to use.
Anything that builds the interest must be a good thing. You wouldn't expect to have EVERY team included, maybe every brand of Morris (each festival could personalise with photos of the teams appearing at their festival, in each category)