I am editing color .dng files, imported from Canon raw files, in Lightroom 6.0. I used to be able to use the graduated filter tool to reduce glare from cloudy skies, etc. Now, the only color that the tool produces is a red-pink. I have tried changing the color, with no effect. I also am unable to adjust the exposure, etc. of the mask. Any ideas about what I am missing? Using LR 6.0 on Intel laptop with Win 7 o/s.
Sounds like you have the tool's overlay turned on. See the checkbox at the bottom of the screen or the View menu.