Color Replacer & Multi Color Replacer Issue: can't reverse

[Hironori Takagi]

When I talked about colors with the staff at our studio, I received the following points.
- Reversing a multicolor replacer is not easy with TVPaint
I heard that it is inconvenient to change the color to a temporary color and then change it back to the original color.
I think "color replacer" not have the same functionality, too. Is it possible to improve FX?

[slowtiger]

I just duplicate the color layer so I can keep the original version. Clients change their mind faster sometimes than I can hit cmd-Z.

[Hironori Takagi]

I think I could not explain this situation completely.
(1) Changed from original color set to a color set that makes it easier to understand the each parts of drawing/painting
(2) Change the colored drawing/painting
(3) Replace with the original color set
When executing (3), I would like to reverse the arrow of the multicolor replacer created in (1), but it cannot be done.
I think (1) to (3) can not be achieved just by duplicating and maintaining the original version.
If the above explanation is still insufficient, I would like to create a demo.

[TVPUSER]

The option to reverse color swaps in the FX panel would be a nice quality of life feature to add