Reply to Master deck LED on Launchpad

Ok, so i got my launchpad all set up the way I want with all the LEDs etc. One thing I can't seem to sort out is getting the LEDs to change colour when they are on the particular master deck. If I hit the deck 1 master button it will light up red, if I hit deck 2 master button it will also light up red, but the deck 1 master button will stay lit up in red and deck 2 will stay red if I hit master 1 again. So basically what I am left with is 2 master buttons always lit up red. What I want is for what ever deck is on master to light up a different colour to to the slave deck. All I can get is for them to stay lit then nothing changes no matter what deck is on master.

Any help?

Thanks