WIP: Support for undo/redo apply colors

[ghutchis]

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[github-actions]

Here are the build results
Avogadro2.AppImage
macOS.dmg
Ubuntu-Latest.tar.gz
Win64.exe
Artifacts will only be retained for 90 days.

[ghutchis]

Okay, I clearly need to revisit this because colors don't apply at all with this patch...