The goal is to not allow any other color schemes with this branded theme. We only want the brand colors for the overall look and because other colors won’t work with the theme, e.g. with the background gradient and blurred icons.
On a forum that only offers a brand look we don’t run into this issue because we can just not offer any other color schemes. But we have a conflict here, because we offer many schemes, but as far as I’m aware we don’t have the option to then disable that option selectively and force a color scheme with a theme.
As mentioned a hack is to entirely circumvent the color scheme system and declare all variables on the theme. I’ve done that just for tertiary values so far. It’s a bit of an ugly approach..