In reality, Vim colorschemes are not that hard to write but there are several benefits to using a template such as RNB:
* you can define/modify variables once instead of messing around with potentially botched substitutions,
* you can distribute a lean colorscheme, free from unnecessary logic,
* you can distribute the source alongside the colorscheme, making it easy for your users to experiment and adapt *your* colorschemes to *their* needs,
* you can focus on the design of your colorscheme rather than its implementation,
* you can start working on new colorscheme ideas very easily.
## What do I need to use it?
[ERB](https://ruby-doc.org/stdlib-2.6.3/libdoc/erb/rdoc/index.html), the templating engine used here, is part of Ruby's standard library so you will need [Ruby](https://www.ruby-lang.org/) to generate your colorscheme. Neither ERB nor Ruby knowledge is required, though.
Each step is thoroughly described in the colorscheme template itself in an effort to make it portable: if you ever decide to distribute your colorscheme you can simply package the template with it.