You could try adjusting the "ui" config on the components you want to be in different colors/themes. If there isn't a built in ui that fits your needs, you can always create new ui's for your components via SASS.
While basic theming is really pretty easy, there's a lot of complex stuff that you can do if you want to, so be sure to check out the resources for theming: http://docs.sencha.com/touch/2-1/#!/guide/theming

