As of version 6.2.23, when zooming in on a piece of the waveform, I started seeing an odd-looking background gray color showing up behind the more intense parts of the wave form. I've attached some screenshot jpegs to show what I mean.

Step 1 shows the original waveform.  Step 2, I select a portion of it.  Step 3, I zoom in via ctrl-N, Step 4, I zoom out a bit using ctrl-O.  I think this coloring shouldn't be there, or at least I don't see a clear utility of it. I'm thinking it might be related to the "More balanced colors" change in 6.2.20.