OK..I made tests as you requested. I adjusted the settings as described below and then watched the screen for 10 changes or until failure.
Looking at the "Options and Preferences" screen under the "Quote Fonts" tab, I tested each of the four font selections individually and in conjunction with the others. For ease of reference, I will label them 1,2,3 & 4.
1 (Top Left - White from the screen shot)
2 (Top Right - Green from the screen shot)
3 (Bottom Left - Red from the screen shot)
4 (Bottom Right - Gray from the screen shot)
Pass - Displayed only the color and/or font/size that was selected
Fail - Displayed the selected color, font and size as well as the over-sized White font
Results:
Single Monitor:
Only 1 - Fail
Only 2 - Pass
Only 3 - Pass
Only 4 - Pass
1 & 2 - Pass
1 & 3 - Fail
1 & 4 - Pass
2 & 3 - Pass
2 & 4 - Pass
3 & 4 - Pass
Multiple Monitors:
Only 1 - Fail
Only 2 - Fail
Only 3 - Fail
Only 4 - Fail
1 & 2 - Fail
1 & 3 - Fail
1 & 4 - Fail
2 & 3 - Fail
2 & 4 - Fail
3 & 4 - Fail
Initial testing was done on the single monitor (laptop) and results appeared to point to the left side choices (1 & 3) being involved. However, with the introduction of the multiple monitors, it appears that theory is out the window. BTW, testing was done on a HP EliteBook laptop and multi-monitor testing used 2 HP LA2405WG flats.
Hope this helps to isolate the issue.