The color determines the stiffness of the boot. Red is the stiffest followed by blue which is still stuff, just not as stiff as red. White is not very stiff and is only available on CCM junior skate sizes. The FIT system is a machine that many LHS' have and use in conjuction with a skate baking oven. When someone gets their skates baked, rather than just putting them on and sitting with your feet in the skates after they're baked, you put your feet into the FIT machine. Basically what the FIT system does is it's this machine that you put put your feet in and inside it has these expandable air bags, they turn the FIT machine on and the air bags inside inflate all around your feet and they can turn up the air pressure to completely compress the airbags around the entire skate to mold it to your foot... i've had it done before and it's absolutely brutal like a torture chamber for your feet. If you've never seen a FIT machine before, the best way I can describe it is it's like a giant blood pressure machine. I would not recommend having this done, try breaking in your skates the normal way and ONLY do the FIT system if your skates are giving you trouble or something. Most CCM dealers have a FIT machine, but some do not. Go to the CCM dealer locator page on their website and it will tell you if a shop has a FIT machine or not.