Starting to look less like a trip to the dentist's office.
Is it possible to add a drop-down box to the top of the site, that'll select a css style-sheet file as your preferred colourway? Cos then we could offer the same thing as what google's just set up in gmail. It could even set a particular section of the css header as your preference -- you can set different classes of tags, eg H3.first { color: blue } and H3.second { color: red } -- so can you select all the 'second' classes, of bgcolor, font styles, table bar colours, etc, which would go together, and set them as visible in your preferences? Because that would be awesome...