[fix] clitools anaglyph should not color black points

clitools/filters/colorcycle.py

@@ -72,7 +72,8 @@ def cycleColor( pl ):
 
     debug(name,"currentColor:{}".format(currentColor))
     for i in range( 0, len(pl)):
-        pl[i][2] = rgb2int( currentColor)
+        if pl[i][2] != 0:
+            pl[i][2] = rgb2int( currentColor)
 
     # change the composant if target reached
     if value <= target and currentDirection == DOWN or value >= target and currentDirection == UP :