What about doing something like this?

http://userealbutter.com/2008/01/06/zebra-torte-cake-recipe/

Someone on here made it - its looks beautiful

http://www.cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1405729

ooh ahuvas that cake looks soooo yummy!!
the rav said about the cmc that it's a 'davar shenichshar' meaning something like there is no chance of it having anything else in it to make it treif therefore it doesn't really need a hechsher- i suppose like sugar and flour.
Leahk - that shop in jerusalem also sells the sugarflair colours ( I think ) these are all fine. If you call sugarflair they will email you all the kashrus certificates.

Ahuvas, that cake looks amazing! Great for dessert, which this will be. I'll pass it on to bride and mother of for consideration. It's totally different from where we were heading.
Thanks,
Cheryl