I need to make a deep blue to represent outer space (don't want to cover a cake in black icing). I was sure I had royal blue, but can't find it anywhere. I have sky blue and cornflower blue. I also have black, red red, burgundy, violet but no idea what to put together to make a deep blue. Any help appreciated and needed immediately!

You could mix your two blues together and than add a little black to make it darker.

Good thinking, and I love your cupcake joke.

A bit of the violet might help as well. Try it in a small 'sample' of the blue before you add it to the whole batch!

I did as suggested, even the tiniest bit of violet, although I don't know if that made much difference. Anyway, it ended up a kind of slate blue and looked like a night sky, which is just fine. My now 6 year old is only going to care about the aliens anyway.

Thank you for the suggestions.

I actually had two people comment on the blue -- asking how I got that colour. They thought it was kind of shiny or metallic. I think it is just because I put so much colour paste in that it was kind of greasy or shiny from the glycerin or whatever is in that stuff.