Everyday Systems

I'm trying to figure out what green/red days are and what does vanilla mean here?

A green day is when you've successfully followed No-S; a red day is when you've snacked, had sweets or seconds (S days are not included in this). Vanilla No-S means following No-S without any modifications.

...and the red and green are the colors that we color our habitcals. (See habitcal above- great tool)

Each weekend is considered S-days. You can snack and eat sweets. People who use the Habitcal color those days yellow. It just means you can't eat like that forever and, on the other hand, they are allowed, so you are not breaking any rules. The recommendation includes allowing two S-days that are not weekend days per month, such as for your birthday or a holiday Monday, if an eating celebration is a very important part of it for you. Actually, it's possible the two "allowed" S-days are not Vanilla No S. Maybe someone with more knowledge of the boards will clarify this.

This is a doable way to live.