Have you noticed this handy feature in the Admin > General section:
When this option is set to Yes, activeCollab will use a client's company logo as the icon for all its projects automatically. If you wish to use a different icon for a particular project though you can still upload one separately via its Project Overview page.
This option can come in handy when you are working on a lot of projects for the same client and you want to make it obvious which client each project relates to.