color every note-head by its note-name

[Kenneth Lee]

Hi,

i would like to color the note-head by its note-name
on the whole score. For example, to color every C with
red and every D with yellow, for example.

i have tried \applyoutput but it only work on the note
that follows immediately. This means i need to
\applyoutput on every notes which is not perferrable.

any help would be deeply appreciated.

Many thanks.
ken lee