We have a big enterprise app to manage a lot of business data. We were using bootstrap and now are changing the design according to Google's Material Design guidelines.
The guidelines offer to use just two colors with no particular meaning plus monochrome. But before that we were highlighting actions like 'save', 'create' and 'approve' with green and actions like 'decline', 'delete', 'cancel' and such with red.
Now I wonder how I would choose colors for buttons with just primary/accent. Maybe we should use something like primary/accent/red with red for dangerous actions? How to choose between green and primary/accent and monochrome for buttons like 'OK', 'agree', 'create', 'approve'?