You hang at GrandLAN? I've stopped by there once (to buy a roll and check out the space) but have not made it back for any actual events...Hey, cool. I actually know the guy that created Gaming Paper (the owner of the gaming center where our games run). I'll ask him about the color thing next time I see him.
I don't know what your American shops are overcharging for, but in Canada you can get 50 sheets at Staples for 12 bucks. Here's a link (that might block your IP if you're not in Canada, who can tell?).