Vim colors conflicting with terminal ones

For most vim colorschemes, they appear different than advertised when I open vim in xterm.

I've been using xterm-256color and set t_Co=256.

A similar thing happens when I use xfce-terminal, but the colors in the colorschemes will vary depending on which colors I set in the terminal's preferences menu. I've read that some colorschemes will rely on terminal colors, and that appears to be what's happening here.

Is there a way to prevent the vim colorscheme from conflicting with the terminal one?