[theme-reviewers] Best practice CSS options

[Tony Crockford]

Not sure if this is the appropriate place to ask, but it feels like I might get a good set of opinions, so here goes.

What would be the best way to implement a style options admin area for a theme - e.g. so that a specific set of CSS values, could be easily changed by non technical users.

Things like header text color, box border colors, box background colors etc.

Every theme I look at does it differently and some respected theme authors say it shouldn't be an option, but that the CSS files should be edited (I think I agree, but have a client requirement for an easily changeable theme).

I'm concerned about performance issues, is there a way to have an options panel write out a CSS file that is then used, instead of having to get over-ride values from the database and dropping them into the header.

TIA for any help.