I tried my best to fix it (I can't actually test on non IOS devices, this was a vacation project). Can you let me know if it works for you now?
The drilling feels smoother than I remember, but I could be misremembering.
It might help to put some sort of solid or mildly transparent background behind the color wheel so that when content scrolls up it appears to disappear behind the color wheel instead of being right there behind it competing with it visually.