What do the colors in the Prostream menu bar mean?

A dark purple menu shows you're on organization level. A light purple one means you're on project level.

In Prostream, the colors of the menu balk on the left indicates which level you're on: 

• Dark purple: organization level (my overview). Here, you can share files with your direct coworkers and other people within your company. 
• Light purple: project level. Here, you'll find all documents and tasks that are related to a specific project that you're working on. From here, you can also share documents with third parties, such as subcontractors.