Bob, they may not work "out of the box", but you should definitely try - as the changes may be very minimal.
The V5 themes are different based on ExtJS V3, where as the 4.95 themes are ExtJS V2. I downloaded a V3 Slate theme and you can download and try different themes from V3 - there are actually some pretty interesting themes (even a 3rd party theme builder) that you can waste hours mucking around with.
It's a credit to how adaptable Aware is (again) that you can make these themes.
