tig does support more 8 colors despite readme

Quoting https://draculatheme.com/tig
> According to the [tigrc documentation](https://jonas.github.io/tig/doc/tigrc.5.html#_color_command) valid colors are limited to white, black, green, magenta, blue, cyan, yellow, red, default. Default refers to the default terminal colors. Due to the limitation on available colors, it appears the best option is to theme your terminal, then adjust the tigrc

As per that, this theme is a bit rudimentary. However tig does support more than 8 colors (perhaps that's a newer feature). See e.g.
https://raw.githubusercontent.com/cbertoldi/dotfiles/master/tigrc.symlink for an example

It should therefore be possible to do a native Tig Dracula theme.