Theres is a special section for this sort of question, but you're in luck I do sugar craft too, so can probably answer your question
- you can't paint a cake with food colouring - not without ending up with a big runny mess at least - you can paint a cake though, but you need to mix up a sort of sugar paint - I use a bun tray & mix my required colours up in the individual sections -
You mix icing sugar & you food colours together to form a paste thats a similar consistency to paint - not to runny, just thin enough to glide on the brush over the cake & be easily applied to the cake & stay put - test your mix on the side if you are not confident - & then just use as you would paint - work quickly, but if you mix is drying quicker than you can work, just add a few drops of water - you can always add more sugar if you add to much
How do I use sugarpaste? Do I need to dry it out so it goes rock hard? How long does that take
No, you can if you want too, but depending on the shapes you need, you can usually build the design before the paste has set.
Can I make leaves in batches, storing them in a container and then assemble days later - How long will it stay edible for
Yes, & they last a long time - I'd say 6 months or more
Also a tip for making leaves is leave them to dry off in the curve of a plate or bowl - this gives them a less "flat" look, more like real leaves.
Do I need to use sugarpaste specifically, or ready to roll/use icing
I think it's personal choice, I have personally never used sugar paste & have managed fine by adding a few drops of my required colour to the ready to roll stuff & kneading it through - you can even "marble" icing this way, so can get some lovely effects. Sugar paste is a more malleable consistency & probably easier to work with, but if you are creative at all, then the cheaper easier way would be to by a block of white ready roll & colour your own.
I've a few cakes on my photos done this way - some flowers made white ready roll & then painted - this is handy if you've a lot to do & not sure of your colours yet - you make decor in advance & paint as needed - the other is dyed ready roll
Also - a fine sprinkle of edible glitter - the proper fine stuff - can hide imperfections
Hope that helps