Thanks for your story
It's nice to hear parents are creative in order to help their kids!
I'm familiar with color codes, but for some reason those just don't get my daughters' attention. I have seen many kids the same way. When they know they have to study, that's it for the whole thing.
This is why I twisted the whole thing around and made it a child's play so they don't even know they are learning.
In ten minutes, my both daughters could name any key on the piano within second of asking it and it was their first time on the piano other than just pounding the keys