Apple has updated DVD Player for Mac OS X to version 3.0.1. The new version includes support for Blue & White G3s as well as PCI-graphics G4s, as the short ReadMe says:
DVD Player update delivers improved performance and stability, as well as support for Blue and White Power Mac G3 and Power Mac G4 systems with PCI-based graphics.
Hardware Requirements
DVD Player update delivers improved performance and stability, as well as support for Blue and White Power Mac G3 and Power Mac G4 systems with PCI-based graphics.Software Requirements
Mac OS X 10.1.1 or greater
You can get the update through the Software Update Control Panel, or directly from Appleis Web site.