Cake

This is the masterpiece of a birthday cake that my daughter Katie made me.

As you can see, you've got a blue stream, running under the doughnut bridge,
surrounded by green grass and speckled with the white rock gardens, while the bike is sitting on the brown singletrack.
I'm not sure if the candles are supposed to be trees or not.
No, the bike in the picture isn't edible.
I told her of all my bikes, no of them are purple.
What's the deal?