How many boxes of cake mix do I need for each 12 inch round? I'm thinking of 3 layers.  Also how many cans of frosting.  Does a few red food coloring drops make pink? Please help I need this for Sunday. Thanks

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You get approximately 5 cups of batter per box mix.  So according to the chart I have attached, if you want 3, 12" layers you will need 22.5 cups of batter so 4.5 boxes.  I would just make up 5 boxes and any leftover batter you can make some cupcakes and throw them in the freezer to eat later.

As for the amount of frosting, you are going to need 9-10 cups depending on how heavy you like to frost the cake.  If you use Duncan Hines whipped fluffy white frosting, one container will yield you about 1.5 cups of frosting, so you would need 6-7 tubs. In my opinion, it would be easier and less costly to just make a batch and a half (or even a double batch and then freeze the leftovers or use on your cupcakes) of buttercream.  The last cakes I made I used this recipe... http://www.completelydelicious.com/whipped-vanilla-buttercream-frosting/ .  I doubled it and had more then enough to fill, crumb coat, put a slightly thicker coat of frosting on the outside of the cake (covered the cakes in fondant) and still had some leftover.  So a double batch of the recipe will be plenty for a 3-layer 12" round cake.

To color the frosting, I would get some gel food coloring (can find at your local craft store) instead of the liquid kind.  The liquid could thin out your frosting, which you don't want.  Add a little bit at a time until you get the color you want (use a toothpick...dip it into the gel color and then dip the toothpick into your frosting...repeat as necessary).

And I just realized that you want to color the cake not the frosting, hence the reveal part of the cake.  So you can use liquid food coloring and just add some drops until you get the color you like.

If  you use my *original* WASC recipe you will need 1 box per layer of cake http://www.cakecentral.com/recipe/7445/the-original-wasc-cake-recipe   Each 'extended recipe" is just the righ amount for a 12"x2" round layer.  Yes, you can color the cake batter w/liquid food coloring but do be aware that in baking it probably will lighten some so you might want to add just another drop or two after it reaches what you think it right :)   As for how many cans of icing - Usually each recipe of frosting using 2 lbs of sugar is recommended for each layer of cake.......But a can isn't near that much so I'm thinking at least 6 cans maybe even up to 12 if y ou use it for filling between the layers.

Ty