Two for one this time. These tools are two peas in a pod:

• Bat is a git-aware drop-in replacement for cat with syntax highlighting.
• Delta builds on bat's syntax themes to provide a pager for git with improved diff highlighting.

I use both with the Nord theme. Git can be configured to use the delta/Nord combo as the default pager by setting

[core]
    pager = delta --theme=Nord

[interactive]
    diffFilter = delta --color-only --theme=Nord

in .gitconfig.