Setting up multiple highlight rules in vim

One way:

highlight EWOL ctermbg=lightgray ctermfg=black guibg=lightgray guifg=black
match EWOL /\%>20v.\+\|\s\+$/

Another:

highlight ExtraWhitespace ctermbg=lightgray ctermfg=black guibg=lightgray guifg=black
match ExtraWhitespace /\s\+$/

highlight OverLength ctermbg=lightgray ctermfg=black guibg=lightgray guifg=black
2match OverLength /\%>80v.\+/

Also available: 3match. Up to three matches can be active at a time. Or you can use matchadd() to create matches without limit to the quantity.

Note: 3match is used by matchparen, so will conflict if you use it.

Use matchadd(), so add this to your .vimrc:

highlight ExtraWhitespace ctermbg=grey guibg=grey
call matchadd('ExtraWhitespace', '\s\+$', 11)

highlight OverLength ctermbg=lightgrey guibg=lightgrey
call matchadd('OverLength', '\%>80v.\+')

To view all matches:

:echo getmatches()

To remove matches use matchdelete().