set-fringe-bitmap-face

set-fringe-bitmap-face is a built-in function in `C source code'.

(set-fringe-bitmap-face BITMAP &optional FACE)

Set face for fringe bitmap BITMAP to FACE.
FACE is merged with the `fringe' face, so normally FACE should specify
only the foreground color.
If FACE is nil, reset face to default fringe face.