\version "2.24.0"

\paper {
  %background-color = #(x11-color "gray20")
  print-color = #white

  #(define (page-post-process layout pages)
     (let ((backgroundcolor (ly:output-def-lookup $defaultpaper 'background-color black))
           (color (ly:output-def-lookup $defaultpaper 'print-color #f)))
       (when (color? color)
         (for-each
          (lambda (page)
            (let ((page-stencil (ly:prob-property page 'stencil)))
              (set! (ly:prob-property page 'stencil)
                    (ly:stencil-add
                     (stencil-with-color
                      (make-filled-box-stencil
                       (ly:stencil-extent page-stencil X)
                       (ly:stencil-extent page-stencil Y))
                      backgroundcolor)
                     (stencil-with-color page-stencil color)))))
          pages))))
}

\header {
  title = \markup { Rendering LilyPond files white on black }
  subtitle = \markup { for screen and projector use }
}

#(define-markup-command (color-sample layout props clr)
   (color?)
   (let ((name (if (string? clr)
                   (string-append "\"" clr "\"")
                   (string-append "#(x11-color \"gray" (number->string (inexact->exact (* 100 (car clr)))) "\")"))))
   (interpret-markup layout props
                     #{\markup \line \general-align #Y #-1 \with-color $clr {
                       \beam #5 #0 #2
                       \typewriter $name
                     }#})))

\markup \left-column {
  \strut
  \line { Any objects with unspecified colour are printed according to \typewriter print-color. }
  \vspace #.3
  \line { Here are samples of pure white along with other colours that may be easier on the eye: }
  \typewriter {
    \color-sample "white"
    \color-sample "ivory"
    \color-sample "antiquewhite"
    \color-sample "navajowhite"
  }
  \vspace #.3
  \line { The background color may also be adjusted through the paper variable \typewriter background-color. Ideas: }
  \vspace #.3
  \combine
  \translate #'(-.7 . -7) \with-color #white \filled-box #'(0 . 50) #'(0 . 10) #.7
  \left-column {
    \color-sample "darkslategray"
    \color-sample "midnightblue"
    \color-sample #(x11-color "gray20")
  }
  \vspace #.3
  \line { Appendix 7 of the Notation Reference lists available colors. }
  \strut
}

{ 1 }