UIColor and CIColor how do they compare and what is the purpose of having two of them?

Question

Recently I encountered some code where trying to get the CIColor property of a UIColor fails. The UIColor was initialized as a simple [UIColor blackColor] and trying to get the

Answer 1

try this(swift version)

 var clcor = CIColor(color: UIColor.redColor())

obj :

CIColor *aCIColor = [[CIColor alloc] initWithColor:[NSColor blackColor]];