I notice that all of the screenshots I see from theme devs use the solid color window decorations that chrome uses on XP. Some of them go so far as to color them in around the tabs section with images (the "berries" themepack, for example).

Is there a way to get chrome to use the solid color window decorations on Win7/Vista? The themes all look much better that way (as they're designed for it, as far as I can tell).

Do you mean that you want to use the theme's 'Window Header' instead of Windows' Aero?

The only way to get the theme's header is by using .crx themes. (I guess that's one good thing about them)