I think I might be changing the cake to a rainbow slab cake and then just icing the same on top..... As above.

What do you think,I'd ice the number 2 as a sort of track........ I just think I could leave the sides plain rainbow, and green with choc 2 ????

What do you think? Have I been thinking about this too much ? Lol ..... I feel a little crazed !
Sounds great, sides aren't important and you'll already have a lot going on on top of the cake