Fireworks use markers to mark where they are going to be shown, and look better in the dark sky (this can also be added through an event).
This section is used to show the markers available for fireworks and how to configure them. Each colour above represents one of the markers available in the editor.
The number down the left hand side represents the marker number that the fireworks will appear next to, i.e. Blue 1. And the other four columns (which are now hard to see after an update) are additional information on the firework effects. From left to right, the text reads:
Fireworks are setup as an event in the scripting side of the map. I won't go into scripting in this tutorial as it is better suited to another.