document skin names

[bltzr]

currently the skin color are named 'Base3', "Pulse1' and so on... which is not so descriptive.

it could be nice to give the user some sense of where they are used.

IMHO the best place for that would be in the theme editor, e.g. by adding a second column to the color list, with every place (or at least some places) where this color is used
(I guess this could be implemented by filling some kind of multimap or something every time a Scenario object is given a color so that there's a way to retrieve where each of them is used - am I being clear ?)