The left light green checked nodes have fully cooked, and the right deep green checked nodes have cooked and changed some parameter on the top node. If I recook the end node, the left nodes will not get recooked except for the end node, but the right nodes will get recooked for all the nodes.
So how can I tell these two states of the nodes? If I check the workitem state with Python, these two will all return “CookedSuccess”.

The dark green indicates that something has dirtied the TOP node itself (e.g. a parameter changing), or one of the input TOP nodes is dirty. This indicates that next time the node needs to generate work items, it will possibly be dirtying or removing existing work items, or adding new ones, based on the parameters.

For example, put down a generic generator and set the Count to 10 and cook the node. Then change the count to 8, which will cause the badge to dim. Right Mouse -> Generate Node, and the last two items will be remove while the first 8 remain.