It'd be a cool feature if coloured devicons worked out of the box. Perhaps include some colour maps for the stock shipped colorschemes and some popular 3rd party ones, a mechanism for users to define their own colour map for colorschemes, falling back to standard terminal colours for terminal vim and the actual colours as per filetype's official colour for GUI vim (e.g. Gulp's #cf4646 for the Gulp icon).

By reading and adapting the section in the README, I've got coloured devicons set up.
I'm using the Solarized colorscheme, so I've chosen the colors that match the palette. You can look at https://github.com/zeorin/dotfiles/blob/e01cebf/.vimrc#L864-L900 for how I did this in my .vimrc.