Feature request --invert-color for picom-trans

[root2185]

I think that could be a nice feature.

[subnut]

@root2185 This feature would need to be implemented in picom first, before it can be implemented in picom-trans.

As you can see in the picom(1) man page,
under WINDOW RULES ➜ Syntax ➜ opacity

Opacity of the matching window. (0.0 - 1.0). If not explicitly set by a rule, the opacity value from the window properties (e.g. _NET_WM_WINDOW_OPACITY) will be used.

picom-trans(1) works by modifying the _NET_WM_WINDOW_OPACITY window property.
In order for picom-trans to support inverting window colour, picom itself needs to implement such a corresponding window property.