Why don't most vim color schemes look as nice as the screenshot when I use them? [closed]

I have downloaded many vim color schemas and tried them out, but many of them don't look like the official screenshot.

For example, vim's own color schema - desert should look like this:

But in my vim, many colors won't display, for example the background.

But some color schemas work correctly.

Why is that?

In the: Edit-> Profile Preferences -> Colors, I select the "use colors from system theme"

Many colorschemes are designed for 256 colors, which is significantly better than a standard 8 color terminal. To make that work, you need $TERM set to a 256 color terminal like xterm-256color.

If you have a 256 color capable terminal (looks like you do from your screenshot if that is Gnome Terminal), set the $TERM to xterm-256color and enable 256 colors in your vimrc with something like:

if $TERM == "xterm-256color"
  set t_Co=256
endif

The Vim wiki has some tips on setting the correct $TERM for different terminal emulators. The easiest way to test this out quickly is to do

TERM=xterm-256color vim 

This will not make colorschemes designed for GUI vim fully compatible with terminal Vim, but will make 256-color colorschemes work, and those are a giant improvement over the standard 8 color colorschemes.

On *nix systems, the very purpose of setting the $TERM environment variable to a terminfo entry that describes your terminal's capabilities, including the number of supported colors is to advertise these capabilities to the applications that will run inside your terminal.

In other words, the reason you set this variable in the first place is to tell Vim (or mutt.. slrn.. ELinks.. etc.) .. Hey.. among other things.. I support 256 colors, did you know..?

As a result, there is no point whatsoever in adding bloat to your vimrc to test the value of $TERM in order to set the value of the t_Co Vim variable. Vim is smart enough to pick up the supported number of colors from the terminfo entry pointed to by the $TERM variable. That's why you set it in the first place..!

In this respect, terminal/console Vim simply follows the *nix model and determines the terminal's capabilities from the terminfo entry and automatically sets the contents of the t_Co variable.

Tried and tested on something like 15 different terminal emulations in a GNU/linux environment.