Great concept, would be perfect if…
I like that red = period and green = luteal/least fertile. But I’d like the option to customise what days are what colours.
For example: I would keep period = red, but I’d love an option for yellow or orange to be my PMS period so that I’m aware that I’ll be feeling more moody than usual. Then I’d choose ovulation to be something like blue so that I know I’m ovulating and that I can choose to try for a baby or be extra careful to not get pregnant. And in the stage post period/leading up to Ovulation I’d have it as pink as I’d start feeling more emotionally upbeat, creative etc.
Obviously not everyone would follow their cycle this way, so simply having the option to customise it would be perfect.