Steps to reproduce:
1. Set a solid yellow background.
2. Create a Shape, a red square.
3. Save and go to home screen. The square is red. Great.
4. In the square's FX tab, set Mask to Background, and Filter to Colorize. Set the color to blue.
5. Save and go to home screen. The square is invisible. Unexpected result.
6. In the square's FX tab, set Mask to None.
7. Save and go to home screen. The square is properly filtered.
It seems that Mask option "None" is bound to an incorrect result.
What's more, the preview doesn't change at all from the red square. It's always red, no matter what filter color is applied.
The preview works better with an image background (instead of solid color), but there's still a mismatch between preview and actual home screen.