Rear brake disc - Is it fu*ked now

Riding the bike back to my mates after my spill last Sunday, the bike would dramatically slow down everytime I released the throttle and it would struggle to get up to even 30 MPH.

The coppers that were following behind that were kindly carrying some broken bits in their car stopped me and said they were seeing lots of smoke coming from the rear wheel

Basically, I was accidentally resting my foot on the rear brake because the footrest was broken.

The brake disc is now a brown colour…

Although the rear brake still works, do I need to replace it?

Thanks.

If the disk/pads started smoking it would have been VERY hot.

Stick a match/short stick onto the swingarm with some blue tack so that the tip is a couple of mm’s from the disk surface, then spin the wheel to see if the disk has warped. Also take the pads out to see what they look like - if it was the front I would definitely replace them, however on the rear you could possibly get away with roughing them up a bit with some sandpaper. Lastly, you may have cooked the fluid - I would change it.

No but i would give the callipers and disks a good clean.

Yeah, I hardly use the rear but its good to have it in emergency and when riding slow around town.

Is there anyway to get the disc back to standard colour?..I was gonna use methylated spirit.

Muc off do a brake disc cleaner. Would definitly replace the fluids though.