Uncompatiable syntax of \set_color

[Udicoudco]

Hello all,

The old syntax of \set_color in 2.3 was
\set_color "lyxcolorname" "color in normal mode"
but now it is
\set_color "lyxcolorname" "color in normal mode" "color in darkmode"
and so all the color schemes in https://wiki.lyx.org/Tips/ColorSchemes
or other places do not work. Is there a way to make the last argument
optional to keep all these color schemes work?

Another question, what is the meaning the of the foreground color that is
documented in Appendix B.3 of the Customization manual, but does not appear in
the GUI?