I know exactly what you are asking for, I want the same thing. I am not vision impaired but i do like the inverted interfaces and software since white with black text is harder on the eyes (i like dark screen light text like the matrix 🙂)
Unfortunately it cannot be achieved with apple's built in inversion. Also, these guys above are suggesting manually editing the images in an image software, meaning they completely missed the point (if i want to look at web images fast on a site, why would i download and edit them all manually, thats a huge waste of time.)
your only option is to leave your inversion settings normal, and explore options with "skinning" your UI. Skinning allows you to download a small program that modifies your operating system to display modified colors, styles, etc. Some of them suck, some of them are really nice. Also, I've never done it on an apple, just a PC. But if you find a good combination of software, you could potentially make all your Finder windows, and OS screens a customized color/style. This can also be done in some browsers via browser plugins/addons. The only limit will be websites. Unless you create or find a browser addon/mod that allows you to "flip" all the colors in any site to the exact RGB inverse (black to white and all colors too) there is no way to view websites in inverse. Apples built in inverse can do this because it modifies the colors directly on the screen (flipping them all automatically, above everything else, on a hardware level, if im not mistaken).
here are some other links i found super fast on google;
http://skinpacks.com/download/windows-7/mac-os-x-skin-pack/
http://techcrunch.com/2014/07/07/mac-os-x-gets-the-dark-theme-weve-all-been-wait ing-for-in-yosemite-preview-3/
http://lifehacker.com/how-to-customize-the-look-and-functionality-of-os-x-161368 0553
http://www.makeuseof.com/tag/top-7-ways-personalize-mac-os-x-desktop/