Rom colorization is a different patched file allowing to have more than 4 colours for your DMD for a specific game. Colorized roms take a long time to make and Most of the authors such as Lucky1, Malenko, NetzZWerg and many others are posting their work on VPUniverse. There are 2 sections 1 for Virtual Pinball and the other is for real Pinball .
Here are most of the Colorized Roms. It links to the original site , make sure to say thanks to the author.
We are recommending to use version 1.7.1 for best compatibility: HERE