diff --git a/bob/pad/face/preprocessor/LiPulseExtraction.py b/bob/pad/face/preprocessor/LiPulseExtraction.py
index 6a4a5899f57a26456e1ca05db0ac532a0162e428..35a88d3135270cec8fac97433fc169a8b26ae09c 100644
--- a/bob/pad/face/preprocessor/LiPulseExtraction.py
+++ b/bob/pad/face/preprocessor/LiPulseExtraction.py
@@ -134,7 +134,7 @@ class LiPulseExtraction(Preprocessor):
           ldms = previous_ldms
           # so do nothing ...
           logger.warning("No mask detected in frame {}".format(i))
-          face_color[i] = 0
+          face_color[i] = [0, 0, 0]
           continue
         frame = frame_rotated
       
@@ -154,8 +154,8 @@ class LiPulseExtraction(Preprocessor):
       ldms = numpy.array(ldms)
       mask_points, mask = kp66_to_mask(frame, ldms, self.indent, self.debug)
       
-      #XXX : be sure that the 3 colors are returned !!
       face_color[i] = compute_average_colors_mask(frame, mask, self.debug)
+      logger.debug("Face color in frame {} = {}".format(i, face_color[i]))
 
       previous_ldms = ldms 
       counter += 1
diff --git a/bob/pad/face/preprocessor/PPGSecure.py b/bob/pad/face/preprocessor/PPGSecure.py
index 33a944bd192c11fae2ac2c25cabe31f4ec01f526..36b201d1554368f9911a27f96776d88a067015b0 100644
--- a/bob/pad/face/preprocessor/PPGSecure.py
+++ b/bob/pad/face/preprocessor/PPGSecure.py
@@ -130,7 +130,7 @@ class PPGSecure(Preprocessor):
       # get the mask and the green value in the different ROIs
       masks = self._get_masks(frame, ldms)
       for k in range(5):
-        green_mean[i, k] = compute_average_colors_mask(frame, masks[k], self.debug)
+        green_mean[i, k] = compute_average_colors_mask(frame, masks[k], self.debug)[1]
 
       previous_ldms = ldms