Why does my dynamic material instance only affect one particle system in a Cascade setup?

Make sure you have the Element Index set to the emitter index value, right now there is a limitation with Cascade/MIDs and Blueprints are working to fix, which might break your setup if you sort/change the draw order in Cascade.

Your Emitter Index starts @ 0.00 on the left and increments up from L to R.

If you have more than one Emitter, you need to set an MID for each Emitter in your system.

If you only want to change the colors of your Effects I suggest giving an instanceParameter a try instead using InitialColor and ScaleColorOverLife modules, it requires far less setup.