How to Use Your Mac's Display Calibrator Assistant

Start with the display's ICC profile and customize from there

Artist throwing paint at canvas

Vital Pictures / Getty Images

Graphics professionals aren't the only people who worry about the color accuracy of their monitors. These pros make their living working with images in one form or another. Making sure the colors they see on their monitors are the same colors seen in a project's final form can be the difference between keeping clients and losing them.

Information in this article applies to all versions of OS X and macOS through macOS Mojave (10.14), except as noted.

Display Calibration for Everyone

Nowadays, just about everyone works with images. They may keep a library of photos on their Macs, print images using color printers, and use digital cameras or smartphones with cameras that make capturing images as simple as point and click.

When that bright red flower you saw in your camera's viewfinder looks muddy on your Mac's display and downright orange when it comes out of your inkjet printer, the problem is that the devices in the chain haven't been calibrated to ensure that a color remains the same throughout an entire process, no matter which device is displaying or producing the image.

Getting photos on your Mac to match the colors of the original images starts with calibrating the display. Professional calibration systems use hardware-based colorimeters, devices that attach to a display and measure the way it behaves in response to various images. These systems are accurate but too expensive for most casual users. However, with a little help from your Mac's software-based calibration system, you can adjust your monitor so that the images you see on your display are a close match to the original versions.

ICC Color Profiles

Most displays come with International Color Consortium profiles. The ICC files, usually referred to as color profiles, tell your Mac's graphics system how to display images accurately. Your Mac comes preloaded with dozens of profiles for popular displays and other devices.

However, color profiles are only a starting point. They may be accurate the first day you turn on your new monitor, but from that day forward, your monitor ages, and three important characteristics—the white point, luminance response curve, and gamma curve—all begin to change. Calibrating your monitor can return it to like-new viewing conditions.

All Macs come with Display Calibrator Assistant, a software-based calibration process.

About the Mac's Display Calibrator Assistant

The Display Calibrator Assistant walks you through the calibration process. The Assistant displays various images and asks you to make adjustments until each image matches the description. For example, you may see two gray patterns and be instructed to adjust the brightness until the two images appear to be of equal brightness.

Before you begin calibrating your display, take the time to set up your monitor in a good working environment. Some obvious things to watch out for include preventing reflections and glare on the display. View the monitor straight on and don't look at the display from an off-angle while color calibrating it. There's no need to work in the dark. A well-lit room is fine.

How to Launch the Display Calibrator Assistant

The easiest way to launch the Display Calibrator Assistant is to use the Display preference pane.

  1. Click the System Preferences icon from the Apple menu or select System Preferences in the Dock.

  2. Click the Displays icon in the System Preferences window.

    System Preferences window on a Mac
  3. Click the Color tab.

  4. Check the box in front of Show profiles for this display only unless you know you need to use a different profile. If you want to use a different profile than the default that is selected, click it to highlight it.

  5. Hold down the Option key while clicking Calibrate to launch the Display Calibrator Assistant in OS X El Capitan (10.11) and later. In OS X Yosemite (10.10) and earlier, click the Calibrate button without the Option key.

    Color tab of Display preferences on a Mac
  6. Place a check mark in the Expert Mode box.

  7. Click the Continue button.

    Display Calibrator Assistant on a Mac

About Your Color Profile

If you already have a color profile in use on your monitor, it is listed and highlighted under Display profile.

If Apple doesn't make your current display, a generic profile has probably been assigned to it, but it is a good idea to check the monitor manufacturer's website to see whether it has an ICC profile you can download. Calibrating the display is easier when you start from a specific profile rather than a generic one.

If a generic profile is your only option, the Display Calibrator Assistant can still create a decent profile to use. It just may take a bit more fiddling with the calibrator controls.

Set Brightness and Contrast on External Monitors

The Display Calibrator Assistant starts by helping you set the display's contrast and brightness.

This step applies to external monitors only. It does not apply to iMacs or laptops.

Access your monitor's built-in controls, which vary from manufacturer to manufacturer. There may be an on-screen display system for brightness and contrast adjustments, or there may be dedicated control surfaces on the monitor for these adjustments. Check the monitor's manual for guidance, if needed.

The Display Calibrator Assistant starts by asking you to turn your display's contrast adjustment to the highest setting. For LCDs, this may not be a good idea, because doing so increases the brightness of the backlight, consumes more power, and ages the backlight more quickly. It's not necessary to crank contrast up to achieve an accurate calibration. You may also find your LCD has no, or limited, contrast adjustments.

Next, the Display Calibrator displays a gray image that consists of an oval in the center of a square. Adjust the display's brightness until the oval is just barely discernible from the square.

Click Continue when done.

Setting display brightness using Display Calibrator Assistant
Coyote Moon, Inc.

Determine the Display's Native Response

The Display Calibrator Assistant determines the display's native luminance response curve. This is the first step in a five-step process; all five steps are similar. You are shown a square object made up of black and gray bars, with a solid gray Apple logo in the center.

There are two controls. On the left is a slider that adjusts relative brightness; on the right is a joystick that allows you to adjust the tint of the Apple logo. To start the calibration:

  1. Adjust the brightness slider on the left until the Apple logo matches the background square in apparent brightness. You should barely be able to see the logo.

  2. Next, use the tint control to get the Apple logo and the gray background to be the same color or as close as possible. Re-adjust the brightness slider as you adjust the tint, if necessary.

  3. Click Continue when you finish this first step.

    Native Gamma screen in Display Calibrator on a Mac
  4. The assistant directs you to complete this process four more times. While the process appears to be the same, you're adjusting the luminance response at different points of the curve.

  5. Click the Continue button after you finish each of the steps.

Select a Target Gamma

Target gamma defines an encoding system used to compensate for the nonlinear nature of how we perceive brightness, as well as the nonlinear nature of displays. Gamma is better thought of as controlling the contrast of a display; contrast is the white level, and brightness is the control of the dark level. Because the terminology is confusing, the conventional approach calls this gamma.

Most Macs manufactured in recent years uses a preferred gamma curve of 2.2, which is the same gamma used by browsers to display images. It's also the native format of PCs and most graphics applications, such as Photoshop.

You can choose any gamma setting you want, from 1.0 to 2.6. You can also choose to use your display's native gamma. For anyone with a new display, using the native gamma setting is a good idea. Most modern displays have a native gamma setting around 2.2, although it varies slightly.

If the monitor is more than a year old, don't use the native gamma setting. Display components age over time, shifting the target gamma away from the original setting. Manually setting the target gamma lets you nudge the gamma back to the desired area.

When you manually select a gamma, the graphics card makes the adjustments. If the correction is excessive, it can lead to banding and other display artifacts. Don't try to use manual gamma settings to push a display far beyond its native gamma.

Click Continue after you make your selection.

Target Gamma screen in Mac System Preferences

Select Target White Point

The target white point is a set of color values that define the color white. The white point is measured in degrees Kelvin.

For most displays, this tends to be 6500K (also known as D65). Another common point is 5000K (also known as D50). You can choose any white point you prefer, from 4500K to 9500K. The lower the value, the warmer or more yellow the white point appears; the higher the value, the colder or more blue it seems.

Use your display's native white point by placing a check mark in the Use native white point box. This option is the safest choice when using this visual calibration method.

Target white point selection screen on a Mac

Click Continue.

The display's white point drifts over time as components of the display age. Even so, the native white point usually gives you the best color appearance, as the drift is not usually noticeable by eye.

Optional Administrator Option

The Display Calibrator Assistant creates a calibration profile that is available only when you are using the Mac. If you want to share the color profile with other users on the computer, put a check mark in the Allow other users to use this calibration box. Click Continue.

Administrator Option screen in Mac Preferences

This option is not present unless you are logged in with an administrator account.

Save the New Color Profile

The Display Calibrator Assistant suggests a name for the new profile by appending the word Calibrated to the existing profile name. You can change this to suit your needs. Accept the suggested name or enter a new one and click Continue to view a summary of the profile, showing the options you selected and the response curve discovered during the calibration process.

Click Done to exit the calibrator.

Assign a name to the new profile