working colours in vim with tmux

.tmux.conf

@@ -0,0 +1,2 @@
+set -g default-terminal 'screen-256color'
+set -ga terminal-overrides ',screen-256color:Tc'

.vimrc

@@ -30,6 +30,9 @@ filetype plugin indent on    " required
 " Colours
 colorscheme base16-default-dark
 syntax enable
+
+let &t_8f = "\<Esc>[38;2;%lu;%lu;%lum"
+let &t_8b = "\<Esc>[48;2;%lu;%lu;%lum"
 set termguicolors
 highlight LineNr term=bold cterm=NONE ctermfg=DarkGrey ctermbg=NONE gui=NONE guifg=DarkGrey guibg=NONE      " line number colours
 " Spaces & Tabs