Open Radar

 
Summary:
UIColor's getRed:green:blue:alpha only works for UIDeviceRGBColorSpace but silently breaks for UIDeviceWhiteColorSpace colors.

This results in having to revert to the CoreGraphics function CGColorGetNumberOfComponents to check if 4 components are returned or 2, which adds branching and redundant condition checks.

Steps to Reproduce:
Create a method that accepts a UIColor as an argument. Attempt to break apart the RGB color components by using UIColor getRed:green:blue:alpha. The method fails and returns false when the user passes a color of type UIDeviceWhiteColorSpace but works as expected for UIDeviceRGBColorSpace. This is a poor experience for users of this API.

Expected Results:
UIColor getRed:green:blue:alpha could and should create the RGB components based on a percentage of the white value. For example red = white * 1.0, green = white * 1.0, blue = white * 1.0. This would be extremely helpful and reduce code redundancy.

Actual Results:
UIColor getRed:green:blue:alpha doesn't work when the UIColor object is a UIDeviceWhiteColorSpace color.

Regression:

Notes: