How do I achieve this effect?

I'm trying to achieve the effect in this image, where the player sprite (in this example, the leaf) is a black and white image. When it's against a white background, it's black. When it moves over a black background, it inverses to white.

I haven't really had any luck mucking about with the blend modes or effects. I don't seem to understand what they are doing. Thoughts?

example image:

https://onedrive.live.com/redir?resid=1 ... ile%2ccapx

total guess work here - but it appears to do what you want.

That's exactly what I was looking for. Thank you very much!

I think I was on the right track at one point but it doesnt actually work 100% correctly unless you're previewing it in the browser so i think i foolishly gave up when it was being weird in construct and didn't bother to see what it was doing in actual practice. Silly me.