Vexing Yet Pointless Questions

Everyone seems to have those questions that have no bearing what so ever on life, yet still seem to bug you. Given the vast pool of useless info available here on the internet, it seems that these answers would be easy to find, but it isn’t always that easy. So, I here by declare this the pointless question post / comment area. If you see a question and you know the answer, fill us in. If you have one, ask it.

My question is when you drink grape juice and then pee, why isn’t your pee purple?