Delta[0] applies syntax highlighting to the code sections of git and diff output, and uses background colors (instead of +/-) to indicate added / removed content. It's written in Rust, and uses the same syntax highlighting library as bat[1]. In fact, any bat configuration that you already have in place (color theme, custom themes/language support) is automatically honored by delta. Delta also infers and highlights substrings that differ between lines (similar to Github, Gitlab and other diff viewers) and removes visual clutter from Git and diff output.
It is Windows indeed. I guess the issue is that my Corp doesn't trust GitHub releases, which is daft when you think about it, since you can in theory clone the repo and compile it (so yeah, releases are blocked, repos aren't).
I think it's possible for me to get zplugin (which is what I use) to compile it on demand, but I've just not bothered to figure the correct options to do so. I just don't see a point. I can live without it, but it is a super useful tool.
At home I still heavily use delta, forgit and bat. Amazing utilities that make life better.
[0] https://github.com/dandavison/delta
[1] http://github.com/sharkdp/bat/