Add luochen1990/rainbow for vim.

.vim/vimrc

@@ -66,6 +66,7 @@ Plug 'godlygeek/csapprox'
 Plug 'gregsexton/gitv'
 Plug 'honza/vim-snippets'
 Plug 'itchyny/lightline.vim'
+Plug 'luochen1990/rainbow'
 Plug 'joshdick/onedark.vim'
 Plug 'majutsushi/tagbar'
 Plug 'motus/pig.vim'
@@ -88,6 +89,7 @@ syntax on
 filetype plugin indent on
 let g:ctrlp_use_caching = 0
 let g:ctrlp_user_command = ['.git', 'cd %s && git ls-files . -co --exclude-standard', 'find %s -type f']
+let g:rainbow_active = 1
 let g:SuperTabDefaultCompletionType = "context"
 let g:vim_json_syntax_conceal = 0
 let mapleader="\<Space>"