Interesting post! Just wanted to note though that Sequoia didn't invest the full $41 Million. The $41M includes investments from Bain Capital and the Silicon Valley Bank as well.
I got everyone in my group to download the app at a restaurant and try out color. It's pretty amazing and is a few UI tweaks away from being a 4-5 star app. If you are trying to build a better color, I would look into the pending patents they have in place. If you can work around the potential legal issues as a user I must say that the idea is brilliant and color is my default method of taking photos already.
The best thing Color could do would be to take a couple of percent from that $41mil and buy one of the really good Camera apps on iOS and Android.
Color is a compelling idea, but any interest I have in playing with it as early adopter is completely killed by the atrocious UI and limited camera functionality I would be subject to.