Colors for menu bar and the scroll bar on emacs 24
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
.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.)
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.