I've had various quirks with color coding with PM before. Beeping on each color code, Not advancing (though set to) on color code. But tonight - using 4.6.7 on a win 7 machine - I'm having dificulty getting consistent results - I can put a color code on a frame that has none but I can't change a code from 4 -3 - but the frame is advancing as though I did change the code???
Then it won't change the color code or advance but will display the cornor buttons (rotates, mag & iptc)
I'll reboot that usually resets these issues.