# Keypoint detection with color images

Are there any known methods to use existing keypoint detectors (which generally work on grayscale images) on color images? of course, one could always add the results of the detector on all three channels to get $3N$ keypoints, but I was wondering if there exist other established methods.

Specifically, I am looking to use a FAST like detector.

Note, that I am not looking for a color based descriptor, but rather for a color based detector.