With the current version of Game Maker, it is not possible to change the color of a particle during run-time without editing a particle type directly or by creating new particle types on the fly.
Gumball CPE (colored particle emitters) allows you to stream particles in whatever color you need as they are created. Instantly choose a new color for your particles, choose random colors for each particles, or gradually change the color of your particles over time.
You can download an executable demo showcasing what it can do below:
It comes with a list of features to help you create your particles:
GMX comes with the following assets:
Contact me for any troubleshooting help or to report a bug!