Almost every area of your Infinity Store can be colour-customised. This includes button colours, text colours, play bar, backgrounds, etc. This is managed in the Styles section of your Infinity Store settings.
To give you as much freedom as possible, you're not limited to one colour for one item. This means you can set your menu text to one colour, your button text to another and your in-store text to a different one. And that's just the tip of the iceberg!
Once you're happy with your style settings you can export these, or, if you're not too confident in your design skills, you can import settings created by someone else. You can find out more about this here.
Pre-made themes can be purchased from airbitthemes.com. Once purchased, you'll receive the file immediately. All you have to do is upload it and voilà - instant theme!
Click here for a full guide to customising your Infinity Store