So, normally you can set sutff like layout.modebar.bgcolor or layout.paper_bgcolor with your typical CSS values, such as "red":

My expectation was that it would also work for using variable, such as tailwindCSS values hsl(var(--primary)). But strangely if I use variable, the inline-styling is stuck on the default background-color: rgba(0, 0, 0, 0.5). As if there's an input sanitization.

I can use variable just fine for other stuff like the chart fonts (layout.font.family = "var(--font-berlin)"), but not for bgcolor. Is it by design?