Five Green Flags:

1. Your company actually puts resources into supporting the purpose.
2. The purpose is actively communicated to everyone in the organization, not just a select few.
3. The company provides data that demonstrates tangible impact related to the purpose.
4. The purpose isn’t solely focused on generating revenue.
5. Processes, structures and careers evolves and adapts based on purpose. (Modified with respect to original reference)

Source: Does Your Company Truly Value Meaning in Your Work?