This Piano App is pretty awesome.
https://chrome.google.com/webstore/detail/color-piano/ihmigmmflfcbhdpdgbkkeojchjhhphnh?hl=enLMs color scale is like the "Isaac Newton Color Scale" from 1704 and the default for the Color Piano is "D. D. Jameson Color Scale" from 1844 that is based on the Isaac Newton Color Scale with intermediate colors for sharps/flats. Comes with Dance of the Red Flutes from the Nutcracker. You can drag and drop MIDI files onto the Color Piano browser window to make them play. To play another song just click "Toggle File Browser" and then download any song you want. For more MIDI files, the following site has a ton of Classical MIDI files but it isn't free (14 day trial):
http://www.classicalarchives.com/midi.html