Not sure about generally accepted but have been familiarized with this theme since Lombardi Teamworks
1. Human Services - Green
2. System Services - Grey
3. Support Swim Lane - Default
4. Data Entry Swimlane - Green
5. Approvers Swimlane - Red
6. Reviewers Swimlane - yellow
7. Notifications - blue
But its a personal choice and you can put a legend comment box about the color scheme you are using