Basically, what I want to make is an object/path which inverts the color of the stuff behind it.

(so that if an object below is blue, it appears yellow, and if it is black it appears as white, etc.) wherever it overlaps with this other object.

Thanks in advance.

Have you checked Blendmodes on Layers already?

It may require a good knowledge of color coding and filters, imho.

No rocket sience:

Simply apply Blende mode:Difference to the object and make sure you have a white object in the background:

I don't really know how to do that... (the whole applying blend modes to individual objects' thing)

The way I made it work was by giving one layer the Difference blend mode and another one above it the Hue blend mode.

Creating a white object on the layer with the hue mode on it did the trick, even if not as optimal.

Still, thanks for the advice, now I know I can do that instead!

Blend modes just work/calculate "against" something. Nothing aka Transparency will not work in the world of image editing.

I just wanted to know how I could get my funny effect idea to work, and thanks you your help, I actually did it.

What does "the world of image editing" have to do with any of that?

It just feels a little out of topic, I appreciate the explanation on blend modes, tho

As I explained already; Blendmodes need a background and foreground image/layer: https://en.wikipedia.org/wiki/Blend_modes

Polygon

No rocket sience:

Simply apply Blende mode:Difference to the object and make sure you have a white object in the background:

This is interesting, but doesn't exactly fit to the needs :

Automatic_M.

Basically, what I want to make is an object/path which inverts the color of the stuff behind it.

The same procedure applies just in a different order: