Coloring of key signature accidentals based on their pitch

[Heikki Junes]

Hi,

in Lilypond 2.19.25 notes and accidental before notes can be colored based
on their pitch:

\override NoteHead.color = #color-notehead
\override Accidental.color = #color-notehead 

Here is an example on NoteHeads:

http://www.lilypond.org/doc/v2.19/Documentation/snippets-big-page#pitches-coloring-notes-depending-on-their-pitch

What I am looking for is to be able to color the individual key signature
accidentals based on their pitch. 

Currently, key signature seems to be a single grob (?) so that only one
color can be assigned to it:

\override Staff.KeySignature #'color = #red

Would it be possible to split the key signature grob to parts in such a
manner that the individual accidentals could be colored, using a kind of
similar code:

\override Staff.KeySignature.color = #color-notehead

best regards,
Heikki Junes