There was, but it's discontinued. If you or your friend is into eBay, there are loads of Strawberry & other coloured clamshell model iBooks up for sale. I think the last versions topped out at 466mhz (G3 of course).
In June a friend of mine bought a gorgeous mint-condition Blueberry iBook on eBay & I set it up to run OS X. Which it does competently, if not blindingly fast.
Actually, there wasn't. There was Indigo (Blueberry), Lime, Tangerine and Graphite iBooks of the Clamshell versions. No other colors. The only Strawberry or "Ruby" colored Macs were in the iMac series.
When my friend bought her Blueberry iBook on eBay I told her sure, I could upgrade it to OS X for her - with a warning that it could be a real slug. Her iBook is a G3 running at 300mhz, with 320mb RAM.
I spent an evening upgrading OS 9 to 9.2.2, then came time to install OS X. I was wary going into it but everything went just FINE. The thing runs OS X much quicker than I thought it would. It's no match for my iMac but I was very surprised at how well this little beauty works. Perfect for what she bought it for - writing, e-mail, surfing the web. Even Classic isn't that bad. Sure, Photoshop would probably be iffy but that's not what she bought it for.
When she came by to pick her Blueberry up I felt proud as a peacock & she was quite pleased that it turned out so well. I took advantage of the occasion to demo my iMac for her husband, who was mesmerised not only by the iMac but by OS X.
Days later my friend said her husband was on her iBook all the time. He's going switch and get an iMac this autumn. Score another for the good guys.