If the green pills are the ones you take at the end of a pack when you get your period, then they're inactive and you don't need to take them. Birth control pills have instructions about what to do in case of missed pills, including when you need to use a backup method. Usually missing one pill is fine. If you've been breastfeeding, that can also provide some protection against pregnancy (although I would certainly not rely on just that).
If you missed one you should be fine. If you missed more than one then you should worry.