3D Viewer color options don't update

[a2k-hanlon]

Latest Printrun source code (6dfdeec). macOS 10.15.4. Python 3.7.7 or 3.6.10 (tried both). Changing the color options for the 3D viewer doesn't work. That's all these options:

• 3D view background color
• 3D view travel moves color
• 3D view print moves color
• 3D view Printed Moves color
• 3D view current layer moves color
• 3D view printed current layer moves color

I haven't checked the 4 tool moves color settings.
This isn't a problem with the 2.0.0rc5 binary.
I have confirmed that the ~/.pronsolerc file gets updated after these options are changed through the options dialog in Pronterface, but even after restarting the program, the default colors persist.

Other settings, including the only 2 non-3D viewer color settings (Background color and Graph background color) do update normally (though changing the Background color requires a restart of the program).