So I finally got around to finishing most of my color font (COLR) and I thought I’d test it in the Windows font previewer, but for some reason the monochrome uppercase A glyph shows behind each character.
Is there something I missed here?
It is most likely an easy fix. As explained in the user manual and in the Create OpenType Color Fonts tutorial there is one technical requirement for COLR fonts:
Glyph index 1 must be the .null glyph.
We will make it more clear in the Color Glyphs section in the user manual, as the link to the recommended glyphs section might be overlooked.