Cannot undo color scheme 'Edit...' changes

[tznind]

1. Add a Label
2. Set its ColorScheme to
3. Add a Button and tab to it so you can see the unfocused/selected color of the label
4. Right click label and select ColorScheme
5. Select Edit Color Schemes...
6. Modify the scheme you used (e.g. set fore color to black)
7. Close edit scheme with CtrlQ
8. Press Ctrl+Z

Expected:
ColorScheme to revert to pre edit (e.g. red on black)

Actual:
Not only is the color change not reverted but instead the last operation is reverted (add button). This is very confusing! Especially if user has been staring at ColorScheme window for a while or made a coffee (why my button disapeared!)