automatic ref counting - Objective-C: ARC forbids explicit message send of 'retain'

Question

I'm new to Objective-C, I try to port an old Objective-C project written in an older version of Objective-C to the new one, but I'm getting the following compiler error:

ARC forbids explicit message send of 'retain'

in 
color = [aColor retain];
or 
color = [[NSColor blackColor] retain];

I was reading about the new automatic reference counting that clang is using now.
I have also tried to use Xcode's refactor function but with no luck... What is the proper Objective-C code that need to replace this old code?

Answer 1

Simply:

color = [NSColor blackColor];

ARC will manage the lifetime of your objects so you don't need release, retain or autorelease any longer.