# ColorSyncProfileEstimateGammaWithDisplayID(_:_:) Estimates the gamma of the profile for the specified display. ``` func ColorSyncProfileEstimateGammaWithDisplayID(_ displayID: Int32, _ error: UnsafeMutablePointer?>?) -> Float ``` ## Parameters `displayID` The system-wide unique display ID (defined by IOKit). `error` On failure, a pointer to an error describing the problem. Optional. ## Return Value A non-zero value on success, or `0.0` in case of error. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)