I put a set of EBC brake rotors from auto shop.
And only driver's side rear rotor's surface is relatively hot(compare to other side rotors after long-term drive) and is partially dark(it's just don't look right to me, and other side's rotors are comparatively brighter than this side).. I think the rotor is not perfectly fitted in axle so the brake pad is keep dragging rotor or sth.. Any suggestions? What should I say to auto shop? My English is short.. Please tell me what to do specifically.

 

I'm no mechanic, but I think sliding a card or a shim between the rotor face and the pads at different rotations of the rotor should tell you if it is grabbing.
Does the pedal feel normal?
Is the brake fluid level normal?
What does "sth" mean?

Question for others that may help: can you reface a warped rotor, or only a grooved one?