when light passes through colored glass, like a stained glass window in real life, whatever it lands on next, caries some of the colors it passes through. this doesn’t seem to happen automatically in blender.
i’m sure i must be missing something obvious. the amount of light reduced by the amount of alpha it passes through is just fine, but the color is missing. i’ve tried all of the settings in materials and textures i could find that looked like ought to fix this, but nothing i’ve tried seems to do so.