Sorry (!) I haven't had time to post. A colleague and I are busy installing a 350 watt LED RGB display over several weeks. Of course the controllers are PICAXE-based.
Attached is a photo of a 200 watt lighting project we installed earlier in 2014. Sculptural panels fitted to the side of a 4-storey building are backlit at night by RGB floodlights (photo taken at dusk). The building is due to be opened early next year. This one has a PICAXE 08M2 driving commercially available DMX drivers.