Cake baking help lol

Hi All,
this is not a diet question, but we are finding out the sex of our baby tomorrow, and wanted to do either a cake or cupcakes that will be blue, or pink (depending on results) for fathers day to reveal it. I can't find a bakery that does it in my city, so might have to bake it myself. Just wondering if any has a receipe or has seen one online. Sometimes the colour doesn't come out well I guess.

Thanks !!