Here is a color icon for your PowerBook hard drive. Even if you do not have a color screen on your PB, your PB will show up with a color icon when you use file sharing with another Mac. This icon was created on a PowerBook165c.
To install the icon, select this file in the Finder and do a command-i to open the “Get Info” window. Click on the icon in the upper left corner and do a command-c to copy it. Now click on the icon for your hard drive, do a command-i to open its Info window, click on the icon in the upper left and then do a command-p to paste the new icon in.
If you ever want your original icon back, just open the Info window for your drive, select the icon, and do a command-x to cut it. The drive’s original icon will be restored.