Quick basics, just about every part that has fonts will have Text Colors setting when click on that part in preview on or in Explorer Tree. Once you have color settings open, click color to change, below preview will be a drop list with colors author has in skin or below that you can add new color, do not edit as color will be used in several places.
There are also text color settings in Miscellaneous, Colors. For menus if you mean File, Edit etc. In Explorer Tree Controls, Menus and Toolbars, many of the subs in these 2 have text color settings, these you wil have to play at. If you have a skin you don't really use much or care for spend some time changing colors ant also font type and size to see what is where.