Function: face-equal

Non-nil if faces FACE1 and FACE2 are equal.
Faces are considered equal if all their attributes are equal.
If the optional argument FRAME is given, report on FACE1 and FACE2 in that frame.
If FRAME is t, report on the defaults for FACE1 and FACE2 (for new frames).
If FRAME is omitted or nil, use the selected frame.