The best I can tell you is that there are controls for the fireworks.
If you select the top parent node, and look under "Extra Attributes" in the Attribute editor, you can see the basic controls for the size and glow of your fireworks explosions and trails.
If you select the "FireworksRockets" particle node, and look under "Clip Effects Attributes" in the "FireworksRocketsShape" node of the Attribute editor, you will se more controls. Select the rocket you want to affect from the drop down menu and you can set the launch frame, burst frame, launch position and burst position very easily. The way the color works is you specify the spread meaning how many of those color chips you want your sparks to use. If you set it to 0 it will onyl use the color chip you've selected (by clicking on the bar below the color). A setting of 1 will use the color you set, plus one to the left and right. Get it? You can edit the colors by clicking on them.
The shapes is uses are under the "FireworksBurstSparksColorCones" and are controlled by the "FireworksBurstSparksInstancer". If you want to instance other shapes, just add them to the instancer.
That's all I can think of right now, so if you have any more wquestions feel free to ask.
I hope this helps.