Trickier than I thought...

I'm planning on making a three layer rainbow cake for Naomi's birthday party (with white meringue icing covering it). There is a white layer, pink layer and brown layer. I started trying to make the layers today (I'll then freeze them until the day before the party), but still haven't made 1 successful layer.

First tried to make the white layer, but didn't divide the mixture into the correct proportions, so it turned out too thin.

I then tried again and at the same time decided to try the pink layer...I had a better technique for dividing the mixture this time, but didn't put enough pink food colouring in, so it turned out just looking like a dirty white layer!

Take #3 is currently in the oven. It is a remake of the pink layer with a stack more food colouring in (what I think would have been most effective would have been to get some food whitener to take the yellowishness of the butter out - I've seen Heston Bloomenthal use it, but I don't know where to get any). I've also decided after seeing how thick the previous one turned out, that I actually want thicker layers than the recipe says, so have put more mixture in the cake tin this time. Will it turn out how I want it to? Or will it not be right and I will feel like I've got nothing done today?