Objective-C, "Shuffling" an NSMutuable Array

[Sisyphus]

I'm not sure, if this is best placed here or in the math/algorithms section.

I'm trying to sort an array so it is as low discrepancy as possible.

int main()
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    NSMutableArray *myColors;

    myColors = [NSMutableArray arrayWithObjects: @"Red", @"Red",@"Red", @"Red", @"Red", @"Green", @"Green", @"Green", @"Blue", @"Blue", @"Blue", @"Yellow", nil];


    srandom(time(NULL));
    NSUInteger count = [myColors count];
    for (NSUInteger i = 0; i < count; ++i) {
        int nElements = count - i;
        int n = (random() % nElements) + i;
        [myColors exchangeObjectAtIndex:i withObjectAtIndex:n];
         NSLog (@"Element %i = %@", i, [myColors objectAtIndex: i]);
    }

[pool drain]; return 0;
}

Which outputs something like:

Element 0 = Blue
     Element 1 = Green
     Element 2 = Yellow
     Element 3 = Blue
     Element 4 = Green
     Element 5 = Red
     Element 6 = Red
     Element 7 = Red
     Element 8 = Blue
     Element 9 = Green
     Element 10 = Red 
     Element 11 = Red

Which shuffles the array, but it isn't as low discrepancy as I would like mainly due to random number seed.

Ideally each instance should be as far away from another one of it's kind as possible like:

Red, Green, Red, Blue, Red, Green, Yellow, Red, Blue, Red, Green, Blue

Any help or suggestions would be great.