I'm upgrading my cakes.
Which chocolate is needed/recommended for spraying pastries/cakes?
Coating or tempered?
If you want to use a paint sprayer, you can use either, provided you thin out the chocolate with cocoa butter. If you are going to thin out with cocoa butter, you might as well use real chocolate--there is no need to temper.
Coating chocolate tastes like, uh... well... best not said.
"Food colouring" and cocoa butter or chocolate don't mix--the colouring is water or alcohol based and it doesn't play nice with fat.
You can buy pre made coloured cocoa butter in bottles, but IMHO this is for chumps. You can buy fat soluable colours and mix your own with cocoa butter. You can find this stuff at Chef Rubber (www.chefrubber.com) or from places like Qzina.
Hope this helps