Quite simply put, MT Style Generator lets you click on any element on the page and a box will appear allowing you to change any of the element’s properties from background color to font faces and styles. After you’re done, you can download the stylesheet that you have just created. The stylesheet is compatible with the upcoming Movable Type 3.2 (under beta at the time of writing this article), which means the stylesheet can be used across any of Six Apart’s platforms, i.e. Movable Type, Typepad and LiveJournal.
the style generator include the ability to switch between 1, 2 and 3 column layouts and the ability to switch from a fixed to a fluid (and vice versa) layout.