I have seen days of the week in colors as far back as I can remember. I never paid any attention to it as I thought it was my thing and was of no bother to me. When the article about other people doing this came out I was surprised that anyone was even studying it. I told my mother and she freaked out and wanted me to go to a doctor! Medical and psychiatric.

I don't see notes in color, just the days of the week such as:

Tuesday, Friday, Sunday--Yellow
Saturday--Red
Wednesday--Sort of a purplish eggplant

This has never gone away and feels normal to me.