The Dagger of Amon Ra released in 1992 on floppy disks. A CD release followed a year later. When the game went to CD, Sierra had to consider people playing the game in Windows 3.1. That operating system has certain colors reserved for its GUI that applications couldn't use. So the art in the CD version is quite different. Sometimes those differences are really obvious...
Hey, where'd my brushstrokes go?
But most of the time, the changes are more subtle. I've made this gallery to more easily view the differences. The floppy version is on the left, and the CD version is on the right.
Credit to ATMachine for providing these screenshots.