Tektronix Phaser 750 User Manual page 141

Troubleshooting Phaser 750 Printers
The inherent difference between these methods of color reproduction can cause
I
discrepancy when you compare this to the printed output from your monitor. For
example, combining the additive colors, Red, Green, and Blue, yields white.
Combining the subtractive primaries, Cyan, Magenta, and Yellow, yields black.
Advanced Features and Troubleshooting Manual 141