How to indicated held chords in CHordNames

[Walt North]

What would be the best way to indicate to the rhythm guitar that a chord is to be strummed and held for a couple of measures? This only happens a couple of times so I'd rather not set up Pitch_squash_engraver if I can avoid it.  For the rhythm guitar player I would be leaving out the note staff so I don't want to attach markup to the staff notes.  I tried adding a dummy Lyric line above the chordname line but that causes errors. I can't add markup to the chordmode.

For example in the below I want the "D" chord to be strummed and held for two measures.

Can I just color or italicize or underline the "D" chords.

    \version "2.24.4"
    
    theChords = \chordmode {
       c1 d d f }
    
    theNotes = \relative c' {
      c1 d d f }
    
    theLyrics = \lyricmode {
      Here1 are the lyrics
    }
    
    \score {
      <<
      \new ChordNames { \theChords }
      \new Staff { \theNotes }
      \new Lyrics { \theLyrics }
      >>
    }