Hi! I have a cake due 12/1 that will look like this. The stripes need to be buttercream. I think I can manage it, but we've had a family emergency, so I'm not going to have the time to experiment. Any hints/tricks? Also, if you know which americolor color is closest to this blue, please share. Sorry to clog up the board with such simple questions. I just need all the help I can get right now. Thanks so much!!