I've only started decorating cakes over the past 6 months. I'm doing it part-time, word of mouth. I used some red bc to write a message on a white cake last night. This morning the colors were just starting to bleed onto the white. Is there a way to keep this from happening? Or is there a way to at lease slow it down?

Use meringue powder in your frosting (on both the cake and the one used for writing). Piping gel is supposed to help, too. There might be some more tricks that I'm not aware of.

What I do is to let the white BC dry overnight, then the next day I put on the red/black icing. I find that if the BC is really dry and crusted over it won't bleed.

There is not a whole lot you can do now that you already have it on there except scrape it off and redo it......I find that if I am using a dark colored writing on a light colored cake that it works better to use royal icing instead of bc for the writing........it ends up being a little crunchy when you eat the cake but it's not too much of a bother if you ask me and it definitely helps it not bleed into the cake.