White text on black background

If you want to print some white text on black background, here's the trick:

\version "2.24"

%% http://lsr.di.unimi.it/LSR/Item?id=281

{
  g1^\markup { 
    \combine 
    \filled-box #'(-.3 . 6.8) #'(-.3 . 1.8) #0 
    \with-color #white 
    "White"
  }
}