What could cause colors to be missing from a printout?

Empty or clogged ink cartridges can lead to colors missing from a printout because they are essential for delivering the ink required to create the desired hues on the paper. When an ink cartridge runs low on ink or becomes clogged, it cannot dispense the ink properly, resulting in blank areas or faint colors in the printout.

A dirty drum can affect the quality of prints but is more likely to cause streaking or smudging rather than outright color loss. Incorrect print resolution may lead to poor quality or pixelation but would not specifically cause colors to be absent. A corrupted driver could lead to various printing problems, including miscommunication between the computer and the printer, but it does not directly affect the presence of ink color that results in missing colors. Thus, an empty or clogged ink cartridge is the primary cause for missing colors in a print.