app-header-background-color not showing working as expected

[ljtilley]

I don't know if this is a bug with home assistant's theming or not, but it doesn't seem like setting the app header background colour works with variables:
app-header-background-color: "var(--background-color)"

When I open the app after setting the theme the android app header seems to stay stuck on the home assistant blue colour and doesn't match the theme.

The workaround I identified was to substitute this definition for the correct hex colour:
dark theme: app-header-background-color: "#393646"
light theme: app-header-background-color: "#eff1f5"

I also tested this with rgba colours since background-color is defined as an rgba value for the dark theme and it didn't seem to like rgba either.