Actually red scenarios were the database affecting versions of white scenarios. No longer in existance.
Black scenarios are a new project, also known as skill based scenarios. The results of your actions are determined by your skills as opposed to random GM disposition. More information can be found in the RPG Centre under the heading 'Skill Based Scenarios'
For more information on White Scenarios, follow the [White Scenarios] link in the board listing at the top of the page. They are non-skill based scenarios, intended for players who enjoy roleplaying and developing their characters. There are few restrictions, so you can be in multiple White Scenarios at the same time you are in a Black Scenario, for example.