I just had my 2005 Subaru Outback at the mechanic to do a brake fluid change, but when I look at the fluid reservoir, the fluid still looks very dark. I have a newer car and the fluid is so clear, I have to look really close to see where the level is. But in this Outback, I’m concerned the mechanic didn’t actually add new fluid. Could it be the old dirty fluid combined with age permanently discolored the reservoir so it always looks dark even if fluid is new? What can I do to make sure there is actually new clean fluid in the system?