What do Blue Egg Raids mean in Pokemon GO?

Pokemon GO trainers aren't sure what to make of the blue eggs popping up in-game. Pokemon GO has a series of in-game markers for different events. From Raid dif

What are Raid Battles? — Pokémon GO Help Center

This egg is glowing what does that mean? : r/pokemongo

How Pokemon Go raids work and tips for completing them

Raid Battle, Pokémon GO Wiki

Rowlett Community Day Pokemon GO Wiki - GamePress

Pokémon Go' Raid: Egg colors, difficulty, how to join, tiers, timer and pass information

Elite Raids are coming to Pokémon GO

Raids - Pokemon GO Guide - IGN

excuse me why is the mega raid egg blue : r/pokemongo

Pokémon Go raid, Raid Passes, and raid counter guide - Polygon

Pokemon Go Raid Boss List: Which Per Egg Star Level, Color?