THCrystalBall class issue

My understanding is that the point of creating this class is to create a better/efficient way to choose a random quote, and so that I can use this class for other things. I got the main part of the assignment to work, but I wanted to take the random text color extra credit a step further and include that in this class for practice.

The code that was successful for the random quote was:

    - (NSString *)randomPrediction {
        int random = arc4random_uniform(self.predictions.count);
        return [self.predictions objectAtIndex:random];
    }

I followed the exact same steps for the random text color and I believe the error in my code is here:

    - (NSString *)randomColor {
        int random = arc4random_uniform(self.colors.count);
        return [self.colors objectAtIndex:random];
    }

This accesses an array I have that looks like this:

    - (NSArray *) colors {
        if (_colors == nil) {
            _colors = [[NSArray alloc] initWithObjects:
                       [UIColor redColor],
                       [UIColor blackColor],
                       [UIColor blueColor], nil];
        }
        return _colors;
    }

The Warning (NOT error) I'm getting is: Incompatible pointer types assigning to 'UIColor *' from 'NSString *' Does my random color code need to return something other than an NSString? My code still works but I don't want the warning to be there.