When using the entity_effect particle you dont get the color options like you would when using dust. This is an inconsistency which prevents using entity_effect or ambient_entity_effect more efficent like you can use dust particles.

particle minecraft:entity_effect ~ ~ ~ 0 0 0 0 10 normal @a

should be changed to

particle minecraft:entity_effect 0 0 0 1 ~ ~ ~ 0 0 0 0 10 normal @a

to be consistent with the new coloring system.