Great idea.  Very unique application.  It was fun playing against my wife.  I'll enjoy toying with it for quite some time and it will be interesting to see if I can really pick up on identifying color components quickly in the future.  I have some thoughts of ways you could take things (in the hopes that it is helpful for you).  But I really like the app so don't take them as criticism...
 
I wish you could enable seeing what you put as RGB and what the actual RGB values are (i.e. 0 to 255).  I know you show it right after but it goes really quickly and I'm watching the other animation so I don't see it.  Maybe that's intentional to make it harder though... I also wondered about other color profiles (like CMYK or YUV), but admittingly that might not be that interesting.  A beginner mode where you can still see the color while you are trying to match it would be helpful for beginners. 

What an awesome way to train your eye for pro-color calibration; I love games where you not only enjoy yourself, but also benefit!

I'm an occupational therapist who frequently works with patients living with brain injury.  I've successfully incorporated iPhone applications during interventions, and think this app has potential to be used for improving visual memory.
My experience is that patients find iPhone applications to be an engaging, non-threatening method of improving skills used in functional tasks.  I would like to have access to a promo code so that I can provide feedback on its utility with brain injured populations. 

The game sounds very intriguing.  I just read about it yesterday.  As an avid photographer and photoshopper, I think I'm your target audience.  I'd enjoy being a beta tester or trying this out to give you some feedback.