Action bars are no longer affected by dark mode in at least v0.22.3, specifically the action bars themselves, the gryphons and XP bars are still working fine.

• WoW Classic Anniversary and presumably others
• Addon v0.22.3

Have fiddled with the desaturation and colour settings and nothing seems to take. It seems like they're not actually falling under the control of dark mode at all. As you can see in the screenshot, the action bars are shown as default while the XP bar and gryphons are clearly in dark mode.

You are right, thanks!
Fixed with e874853 (simple 1 variable change)