Changing colors on watchface

I’m trying to make my watchface gradually change colors, using red, green, and blue layers with transparencies. However, the blend results aren’t coming out as I’d expect. If both red and green are showing with 50% transparency, for instance, I’d expect the resulting color to be yellow. Instead it comes out as this brownish color.

Is there a way to make colors blend in a rational way?

One of 2 things:

  1. set another layer under them, that will be pure white
  2. make sure that the lowest layer is always 100% transparency (keep 50% for red, but green under it should be 100%)

Also, you might need to experiment what is better:
Image with color on it from the beginning, or a white image with tint color set in the Facer.

Well the tint would definitely be better, but is it possible to do conditional logic with tint?

Having the white layer undermeath doesn’t seem to help at all - I already had the “background color” set to white.

No, currently one cannot add conditions into color field.