Brake Problem..?

[M3ACS]

Hi

My CSL has APs all round, and over the past ten months have performed awesome without fault.

However over the past week ive noticed what feels like brake fade even in normal driving, this is constant and even around town and not just on spirited runs.

Ive checked the pads - Plenty of meat!
Discs - Look fine!

Brake Fluid - There's fluid in there, although it looks a little pail at the top and darker nearer the bottom unsure if this means anything..

Anyhow in addition to this ive just washed the car, really cleaned the wheels as they were really dirty - Will come back to this point

After the wash went for a little drive, just come back home and the wheels are filthy as if the brakes have leaked every where..

Touched the brakes they look fine just got a load of brownish liquid on them as do the wheels.

So im confused as to what the problem is, can anyone help?

Im keen to resolve ASAP as im due at Cadwell soon