I mentioned this a while ago, but I've been doing some work for a mobile game company on a matching game. I was asked to help design the look for the theme store, where players can purchase different themes for their backgrounds and cards, such as themes based on space, flowers, Christmas, etc.
The design was supposed to allow players to scroll through a list of choices, showing an exit button, the prices for each theme, and how many coins (in-game currency) the players had at their disposal. I think giving them a small preview of the theme was also important--just enough to pique their interest without displaying every last detail before it was purchased.
I was asked to rework the color scheme a few times for something more appealing. I'm not sure yet what colors subconsciously influence people to buy things... But personally, I find lighter elements against a predominantly dark background more easing on the eyes. Really bright colors can be straining after a while so I tried to keep that in mind.