I know there are several apps in the music world (such as *functional ear training*) that 'train' you to recognize certain intervals within keys by playing notes and then having you pick what the interval is. I'm wondering if there are any similar apps for the photography industry. For example showing various colored lights and having you pick the approx color temperature/white balance. It would be interesting, I think, to be able to become more perceptive to these sort of things rather than just relying on a light meter or some such device, and i think an app would be a good way to do this. Do you know of any apps of this sort or similar that are used to improve visual perception of light and color?