So if you use one of pre-defined skins, then you need to use custom css to change colors. If you will send us link to page where you would like to change menu item colors, we will tell you how to do this.
Ok, thanks. So to the menu items color, you need to use:
#Top_bar .menu > li > a { color: #FFF; }
however, we do not understand how exactly you want to change hover color. You said that you want menu items to be blue on hover but the background is currently blue as well.
Comments
menu items color you can changed under Theme options > Colors > Menu & Action Bar section.