Select FlamingoThemes.Charcoal, go to the "Advanced" section and write
it will result in solidColor.png
If you write
it will change only the places where @text-muted is used in .less files, see transparentColor.png
If the color is set using a backwards compatibility mapping and the initial color is
even if the mapping is done
the transparent color fails to be set, and relies on the fallback color.
So there might be a problem with transparent colors that use parenthesis () and Velocity.