Consistency takes many shapes
You and your boss are advocating for different systems of rules. The question is, which one will align with your users' needs in practice?
Lighter shades to signify navigation level
The big question is not consistency but why? Do your users need to know they're adding from a deeper level? Does this make any difference to the user's workflow or the resulting item?1
Identical color for identical actions
This approach takes consistency more literally. Users will quickly understand your meaning. The system you're setting up here is a 1:1 relationship between color and action.
1 If this distinction is important, make sure the experience makes that clear somehow. Button color is too subtle to deliver such a nuanced message.
Option number two works if:
- You don't have a lot of actions and color variation can be used effectively to differentiate.
- Your workflows are simple and you don't need to emphasize different actions from view to view.
Color can communicate workflow
Based on OP's comment: Same color, different labels.
In a more complex environment, it can be useful to use color to emphasize the current workflow's needs. For example:
- In a list of users, the primary action might be
Add
.
- On a work item detail view, it might be
Complete
.
- On a customer detail record, it might be
Call
.
Your system could define green as the primary action color. This enables the user to quickly find the next action on any given view. It also means you won't need as many colors as a 1:1 color to action system requires.