Single and double quoted strings are not colored in vimrc when referencing Plug items

[nickjj]

For example:

" Specify a directory for plugins.
call plug#begin('~/.vim/plugged')

" Atom One Dark / Light theme.
Plug 'rakr/vim-one'

With Vim One (either dark or light), the '~/.vim/plugged' will be colored up green, but the rakr/vim-one line will be the same color as Plug which in the end, isn't colored up. Other single and double quoted strings in the vimrc will be colored up.

Here's a screenshot: