`.vimrc` unsuccessful in setting highlight style

Question

1) To underline misspelled words, I can execute the following in an open buffer:

:hi clear SpellBad
:hi SpellBad cterm=underline
:set spell

2) However, if I write in my .vimrc the first two lines, namely:

:hi clear SpellBad
:hi SpellBad cterm=underline

and when I open a file, I execute :set spell, misspelled words are highlighted in color, but not underlined.

Why are the .vimrc settings in 2) overridden? How can I get the same result as in 1)?

Answer 1

They are likely overridden by your colorscheme of choice (even if it is default).

My suggested fix is

augroup colors
  au!
  au ColorScheme * hi whatever
augroup

Answer 2

D. Ben"s answer is correct one but a bit terse.

I also answered a similar question with detailed solution at How to set a colorscheme that still shows spelling errors?

au is very useful!