This article explains how to use your Mac's Display Calibrator Assistant to improve color accuracy. Instructions apply to all versions of OS X and macOS through macOS Catalina (10.15), except where noted.
Apple Macintosh – Display Calibration Assistant
The easiest way to launch the Display Calibration Assistant is through the Display preferences pane.
Click the System Preferences icon in the Apple menu or select System Preferences from the Dock.
Click the Displays icon in the System Preferences window.
