How to change Emacs command line color

The bottom part is called minibuffer if I recall correctly.

M-x customize-face
minibuffer-prompt

Two possibilities for this one:

One: http://www.gnu.org/software/emacs/windows/old/faq4.html Just scroll down until you see the part about color, in which it gives you the libraries where you can change emacs colors using RGB values.

Two: http://www.emacswiki.org/emacs/ColorTheme This one's definitely a lot more robust than you need, but it's basically a 'plugin' of sorts that allows you to customize literally any color in emacs, or use premade color themes.