I am making a paint can cake this week for contest at work. Theme is Paint the Courthouse Purple. It is to raise money for Relay for Life. Anyway...I am looking for ways to make the "Paint". I thought about thinning down my buttercream and just using that. Is there a better way? I thought it would be nice to use something that would help give it the wet look. Any suggestions?

I'd think that piping gel would really give it the wet look you're looking for. But buttercream would be fine too. If it's going to be eaten I'd probably stick with the BC since I wouldn't want to serve anyone a big dollop of piping gel. Blech

I made lava for a volcano cake and just used runny royal icing....I poured some over the top of the cake and just let it run....on the way down the sides it firmed a bit and stayed put through a 3 hour car ride.

Couldn't you use melted candy melts or color some pourable white chocolate ganache?

What about melted candy melts..you get true colors, taste good enough to eat and should set shiny.

I agree about the piping gel. Would be ok in small amounts but not in the large amount I'll need. Eww! I like the royal icing idea...may have to give that a try.