Why does my external monitor look washed out?

Check whether the Mac's output range matches the monitor's input setting. A mismatch between Full Range and Limited Range can make contrast look wrong. It is one possible cause, not a diagnosis of every faded image.

On Apple silicon, open App Menu > display > Color Mode, usually beneath the more-options chevron. Read the range tag on the active format. The menu requires a connected display with available connection-mode information.

If the monitor expects full range, choose a supported Full Range format. If the connection uses Limited Range, set the monitor's own input-range option to match, where available. Consult the monitor's menu or manual for its terminology. Changing the Mac's format does not prove that the monitor interprets it the same way.

Compare the image after the two ends agree. Do not use brightness or contrast adjustments to compensate for a known range mismatch. If the range already matches, this check has not identified the cause. The monitor's picture settings and color configuration need separate investigation.

Follow the output-range and color-mode tutorial to record the starting settings, match both ends and check the physical result before saving a format.

The available formats depend on the connection and refresh rate. See Color Mode and Color range. If a working format later changes, see keeping your preferred color mode.