of `set-face-underline-p'.
This actually sets the @code{:slant} attribute.
@end defun
-@defun set-face-underline-p face underline-p &optional frame
+@defun set-face-underline-p face underline &optional frame
This function sets the underline attribute of face @var{face}.
Non-@code{nil} means do underline; @code{nil} means don't.
+If @var{underline} is a string, underline with that color.
@end defun
@defun set-face-inverse-video-p face inverse-video-p &optional frame