Hmm, while mucking around trying to tweak the look of my blog, I realised that Internet Explorer really is a backwards browser. It doesn't support alpha transparency in PNG files, which means to get my theme to look half-way decent in IE, I had to convert them all to GIFs, and making tweaking of the colours a heck of a lot more complicated in the process.
I've been using FireFox for ages, so I only noticed this when checking browser compatibility of my site.
In the spirit of the whole FireFox Rules! campaign, I've added a little button at the bottom of the page to help share the love. Get your copy of FireFox today!
Oh, and Quinn, these colours aren't permanent. It's a process 
[Edit] Seems like IE7 will support PNG alpha, whenever MS may feel like releasing it.