I learned from the music notation project that if you color the keys with alternating colors (assigning each key to one of the two whole tone scales), each chord and scale follows the same pattern of color changes in every key. For example, every major scale is three notes of one color followed by four notes of a different color. This is helpful when transposing and learning to play in different keys. My first attempt at fully coloring each key made it a bit harder to read and play, since my brain is so accustomed to the conventional color scheme and I still need to look at the keys often. So now I just color the top of each key with a piece of electrical tape, and I can easily ignore the whole tone coloring when I'm not using it. I'm having fun using the colors to better understand the relationships between notes in different keys; you might too!