color notes - strange colouring

[bb]

song = {
      \override NoteHead.color = #red
      \override Stem.color = #red
      \override Beam.color = #red
    e8 d
      \override NoteHead.color = #black
      \override Stem.color = #black
      \override Beam.color = #black
    d c
  }

\score {
  <<
    \new Staff \relative c' {
        \song
    }

    \new TabStaff {
       \tabFullNotation
    \stemDown
     \song
    }
  >>
}