Particles for behavior.send_event can no longer be transparent with #00

Release_4664666

Summary:
When setting the `particle_color` tag inside `event_choices` of `minecraft:behavior.send_event` to something like #00000000 the alpha bits are ignored and particles show up as black (or whatever defined color) instead of transparent. I believe the format is ARGB (AARRGGBB)

Impact:
Particles show while sending an event when we don't want it to. For example, if we had an invisible entity that sent events to other entities, the player would see the particle effect.

Repro Steps:

1. Add attached JSON into world's behavior pack
2. Summon Cow
3. Summon Zombie adjacent to Cow

Observed Results:
Cow gives off black particles

Expected Results:
Cow gives off no visible particles

Screenshots/videos attached:
n/a