How to bring back the colour to the dots in a fretboard in Lilypond 2.20? - lilypond

Question

I need help with a rather obscure problem. But important to me as an educator.
In Lilypond 2.18 and before, using the colouring scheme from the snippets (https://t1p.de/b7s8) I was able to colour the dots of the fretboard with the root note colour. I would simply use the code:
\override FretBoard #'color = #color-notehead.
(top part of the attached image)
When I upgraded to Lilypond 2.20, the colour from the dots vanished, replaced by black (as in the bottom part of the attached image).
I didn't change any of the code (which I can provide if needed).
Now, with
\override FretBoard #'(fret-diagram-details dot-color) = #'white
I can override the dot-colour to some static colours - but it's a far cry from the beauty of dynamically coloured dots.
Could someone advise where this went wrong?
Attached image with 2.18 and 2.20 renditions of the same code
Here's a Minimal code sample, which colours dynamically the dots by it's root note in 2.18, but leaves them with a static colour in 2.20
\version "2.20.0"
\header { title = "Guitar Chords"}
{
%Chords
\storePredefinedDiagram #default-fret-table \chordmode {a}
#guitar-tuning #"o;o;2-2;2-3;2-4;o;"
\storePredefinedDiagram #default-fret-table \chordmode {bes}
#guitar-tuning #"1-1-(;1-1;3-2;3-3;3-4;1-1-);"
\storePredefinedDiagram #default-fret-table \chordmode {c}
#guitar-tuning #"3-3;3-4;2-2;o;1-1;o;"
}
%Colour map
#(define color-mapping
(list
(cons (ly:make-pitch 0 0 NATURAL) (x11-color 'red3))
(cons (ly:make-pitch 0 5 NATURAL) (x11-color 'blue3))
(cons (ly:make-pitch 0 6 FLAT) (x11-color 'magenta3))
)
)
%Compare pitch and alteration (not octave).
#(define (pitch-equals? p1 p2)
(and
(= (ly:pitch-alteration p1) (ly:pitch-alteration p2))
(= (ly:pitch-notename p1) (ly:pitch-notename p2))))
#(define (pitch-to-color pitch)
(let ((color (assoc pitch color-mapping pitch-equals?)))
(if color
(cdr color))))
#(define (color-notehead grob)
(pitch-to-color
(ly:event-property (event-cause grob) 'pitch)))
chordNames = \chordmode { a2 bes c }
\score {
<<
\new ChordNames \chordNames
\new FretBoards
{ \override FretBoards.FretBoard #'size = #'2.0
\override FretBoard #'(fret-diagram-details finger-code) = #'in-dot
\override FretBoard #'(fret-diagram-details orientation) = #'portrait
%This command changes the colour of the fretboard (and used to change the dots in 2.18)
\override FretBoard #'color = #color-notehead
\chordNames
}
>>
}

Answer 1

On the Lilypond Forum, Harm posted a hack. When added, it colours the dots in the same colour as the fretboard. It's a temporary solution, but works as a charm.
\override FretBoards.FretBoard.before-line-breaking =
#(lambda (grob)
(ly:grob-set-nested-property! grob '(fret-diagram-details dot-color)
(color-dot grob)))