I need to make some decorations for on the sides of a cake and was going to do them in color flow but am worried about the pieces breaking down as they will be put onto buttercream.  Does anyone know how long they would be okay on the sides of a cake, I would be doing the cake the day before the party.  Am debating about doing the color flow vs melting colored choc and doing the decorations that way and putting them onto the buttercream.  It is just small letters and a logo so it is nothing big that would be heavy if I use chocolate.  Any suggestions and/or experience would be greatly appreciated.

AThere could be bleed issues with color flow on buttercream because royal icing (ie color flow) does not like grease. It would probably be fine but if you have to have it put together the night before, I'd do candy melts or fondant.

Thanks Sassy.  That is what I was thinking too but just wanted to get some opinions on what others have done.  I could wait and put the color flow pieces on the morning before it is picked up but I never like to wait until last minute.