This is a simple eyecandy effect comprising a cloud of small, wandering sprites like those used for air bubbles.
It is intended to be used also as a light source, though this is not mandatory. Marshlights can be used to provide spooky illumination for areas where other light features may be inappropriate, such as outdoors at night or islands floating in the void.
Because they are fullbright and animate in an obvious, semi-random manner, they are also easily spotted and can be used to attract the player’s attention to important items, indicate route choices or hint at secrets.
There are seven different colors available and are chosen by setting the key “color” with a numerical value as follows:
0 = white ( default )
1 = bluish white
2 = blue
3 = green
4 = orange
5 = red
6 = purple
If your editor doesn’t like using the “color” field, you can set the “frame” field instead.