2 Cosmic Black (one Japanese and one European, both are still for sale).
1 Flare Red (Japanese).
1 Cosmic Black (EUR Capture Unit).
1 Aqua Blue (JPN Capture Unit).
Now, when I successfully sell the 2 Black 3DS's, I would either get a Midnight Purple (USA Capture Unit) one, or an Ice White (European) one.
If I do both, I'd get a Pearl Pink (American) one too, so it would be a pattern of Red/Blue (Japan), White/Black (Europe), and Pink/Purple (America).