Colors for menu bar and the scroll bar on emacs 24

1. Emacs 24 does not have a new color system. What it has that is new is a Customize interface for custom themes, which are different from but similar to the color themes of library color-theme.el.

2. I think you mean the mode line and not the menu bar. (To change menu-bar appearance I think the only recourse might be Xresources.)

3. The faces to customize are these:

   • scroll-bar

   • mode-line

   • mode-line-inactive

   • mode-line-emphasis

   • mode-line-buffer-id

   • mode-line-highlight

You can customize any of these using M-x customize-face. Or you can define a color theme or a custome theme that uses them.