When editing the photos below, after paying a graduated filter the shadows in the image turn bright blue, the blue colour then disappears when I switch back to the library module. The blue noise doesn't appear when I export the image or in the filmstrip or navigator.
Lightroom CC 2015.3 release version 6.3 (Mac)
That the clipping overlay. Click the white triangle in the upper left corner of the histogram to turn it off.
Great, thank you so much!