I always forget how to do this and I need to write it down:
Turn on syntax highlighting with:
If highlighting looks to dark, then you are probably using dark background, so set it to achieve better readability:
To make these two changes permanent, edit ~/.vimrc file and enter:
syntax on set background=dark
To turn of syntax highlighting do:
To go back to light background do:
or delete the lines from ~/.vimrc file.