54F3

This result has the RGB levels being subtracted. The yellow colour on the keyhole (195, 195, 71) were subtracted from the variable colour (255, 255, 0). 195 - 255 = 0, 71 - 0 = 71 which made the resulting colour on the keyhole. I wonder what would result if a triple digit subtracts a double digit.

More importantly, using 195, 195, 71 on the keyhole box might back the hole black.