New custom theme, canvas graphs: foreground color or light/dark setting

If you make a custom theme, performance graphs get the foreground color default set to the light theme facelift, which makes the text in the canvas black. When your new custom theme is a dark theme, this makes the graphs difficult to read.
See examples: https://forum.checkmk.com/t/manager-asked-for-a-bit-more-color/40371/

Werks 11835 & 12996 removed the option to set foreground color for not being useful, while it is useful in above situation.

So either give back the option to set foreground and background color. Or alternatively an option in your custom theme, like in theme.json, to set if the theme is a light or dark theme, so the foreground and background colors are set according the default light or dark theme.