I already know the basics of some of the natural food colourings, like spinach for green, beets for purple, turmeric for yellow... but the one that I knew I can't live without is the one that was harder to find. Blue. Fear not, because I found a link to a recipe for natural blue food colouring, and it turns out I had an idea what it was too. I once heard of dying yarns with red cabbage to get a beautiful shade of blue, but I thought it was only achieved by adding alum powder, which didn't sound tasty at all. This recipe doesn't contain anything nasty, so I hope to give it a try and maybe save my child from food colouring related illness... at least at home.
here is also a link to wikipedia on the subject of natural dyes that may be helpful / interesting