Yosemite turns on "reduce transparency" at every login or wake after battery failure Recently, I was using my rMBP on battery power, with about 20%-30% remaining battery, according to the battery indicator. It suddenly shut off, and would not power on (not even showing the "battery low" screen) until I plugged in. After starting back up again, Yosemite now keeps enabling the "reduce transparency" option when I log in or lock the computer.

A SMC and NVRAM reset was done, and I also tried repaired the filesystem and file permissions. Both actions did not help.
are you using Duet? If so, that is the problem.