I've noticed that there is a setting that allows you to customize the color of the forums, which is cool, but I use three computers regularly, two of which run two different operating systems. This setting seems to be on a per-browser basis (probably a cookie, but I'm only guessing). Is there any way for the server to associate this with our user account? This is a very minor thing, and not probably worth any time investment, but it would be cool if my dark green forums could appear on every computer I use.

There's a theme selector, but I have no idea which color selector you're talking about. The theme is set for each user in the database on the server, not by a cookie.

If this green color setting is being set by a cookie, then just set it on each of your five device/OS combinations and you're good to go.

Top right, color "doohicky".

Your forum theme selection is saved on the database, the color selector is saved in the cookie that saves your login. My recommendation is what Malem said and set it on any device your using.

You may also want to consider using the "sync" capabilities of Chrome or Firefox if you use the same browser on multiple devices. This will sync cookies, saved passwords and other data across all your devices, improving the browsing experience.

Firefox: Firefox menu -> Options -> Options, click "Sync" then follow the links/prompts from there.

Chrome: Enabled by default when you're signed in with your Google account (go to the Settings page to manage sync settings)