My PS2 is noisier when running blue disc ?

I bought a game , and , well , it wasn't in a store , so i checked the back of the disc for scratches and i noticed it was a blue disc , anyway , like I was saying , i bought the game and tried it on my PS2 , it worked fine but I noticed my PS2 started being noisier (Fan started working faster and was just the sound that makes with silver discs but a bit higher) unlike when i play with silver discs , why does that happen and can it DAMAGE my PS2 ?