# init(calibratedRGBWhitePoint:blackPoint:gamma:matrix:) Creates a calibrated RGB color space. ``` init?(calibratedRGBWhitePoint whitePoint: UnsafePointer, blackPoint: UnsafePointer?, gamma: UnsafePointer?, matrix: UnsafePointer?) ``` ## Parameters `whitePoint` An array of 3 numbers specifying the tristimulus value, in the CIE 1931 XYZ-space, of the diffuse white point. `blackPoint` An array of 3 numbers specifying the tristimulus value, in CIE 1931 XYZ-space, of the diffuse black point. `gamma` An array of 3 numbers specifying the gamma for the red, green, and blue components of the color space. `matrix` An array of 9 numbers specifying the linear interpretation of the gamma-modified RGB values of the color space with respect to the final XYZ representation. ## Return Value A new calibrated RGB color space, or `NULL` if unsuccessful. In Objective-C, you’re responsible for releasing this object by calling [`CGColorSpaceRelease`](/documentation/CoreGraphics/CGColorSpaceRelease). ## Discussion Creates a device-independent RGB color space that represents colors relative to a reference white point. This white point is based on the whitest light that can be generated by the output device. Colors in a device-independent color space should appear the same when displayed on different devices, to the extent that the capabilities of the device allow. For color spaces that require a detailed gamma, such as the piecewise transfer function used in sRGB or ITU-R BT.709, you may want to use the function [`init(iccBasedNComponents:range:profile:alternate:)`](/documentation/CoreGraphics/CGColorSpace/init(iccBasedNComponents:range:profile:alternate:)) instead, because it can accurately represent these gamma curves. --- 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)