Set rgb color for default theme in iOS

Hi everybody,

I would like to set the primary color for the default theme with rgb values.
Under windows (firefox) it is possible:

but in iOS (HA App or Safari Broser) i get only a palette of colors to choose:

How can I set the colors of the default theme more specific?
Maybe it is possible somewhere in the .storage folder? but I couldn’t find where.

I know its possible to create a custom theme but I want also switch from light to dark theme automatically without creating an automation for this.

Thanks for your help :slight_smile: