What are the differences in the frameless skins?

RoboHelp 2020 provides several skins for Frameless output, but are there any functional differences among the various these skins (aside from TopNavigation) ? I'm just wondering what the reason might be to start with, say, Studio rather than Orange, when I'm going to have to redo the fonts and colors to meet corporate branding requirements. I can't really tell much difference in the output. (Apologies if this has been asked and answered; I couldn't find it anywhere.)

And, related question (I think I know the answer but I'll ask anyway): Is there any kind of reference information that explains how all the settings in a skin are used? The Skin Editor is good as far as it goes, but it doesn't show every possibility for customization (maybe that's not even possible anyway).