First off, thank you for considering contributing to this Neovim configuration! It's people like you that make Neovim such a great tool.
If you've noticed a bug or have a feature request, make sure to check our issues (https://github.com/xscriptor/nvim/issues) to see if someone else in the community has already created a ticket. If not, go ahead and make one!
If this is something you think you can fix, then fork this repository and create a branch with a descriptive name.
A good branch name would be (where issue 325 is the ticket you're working on):
git checkout -b update-colorscheme