The idea:

• What do you need? Entities coloured differently (the background colour), not just in blue. To be able to choose other colours for other entities, like green, yellow, pink and so on. Or each external database's entities to be coloured differently automatically. Any that is easier to implement.
• What could it improve? Visibility and Demonstration of the external databases (producer modules) in the consumer module.
• Who would benefit from that? Enterprise application developers. When Databases are added via Managing Dependencies into the consumer module they all look the same.