Chord Colors is described as 'Every note gets a color from the circle of fifths. Notes that sit next to each other on the wheel get colors that sit next to each other, so you can see which chords belong to a key before you have learned why. You do not need to read sheet music to use any of it' and is an app in the audio & music category. There are more than 10 alternatives to Chord Colors for a variety of platforms, including Web-based, Android, iPhone, iPad and Windows apps. The best Chord Colors alternative is EarMaster, which is free. Other great apps like Chord Colors are Noteful: Learn to Read Music, Guitar Dashboard, Visual Guitar and musictheory.net.