One thing to note, the "Green Advantages" you see aren't necessarily providing "Advantage"

Advantage in D&D is a specific bonus where your dice are rolled twice and you take the best result.

Things like High Ground bonus don't provide Advantage, it just provides +2 to your attack rolls. Magical Weapon also doesn't provide Advantage, it just applies +1 to your attack and damage rolls.

Typical sources of Advantage are:

- Hiding/Being Invisible
- Reckless Attack
- The target being Blinded/Entangled
- The target being Prone/Sleeping and within 3m of you
- The target being affected by Guiding Bolt

Sneak Attacks require this Advantage to occur (Or having another ally standing within 1.5m of the target, which is the most common way of enabling Sneak Attacks. Heck, the ally doesn't even have to be in combat with the enemy for this to work which is a common way to utilize Arcane Trickster's Mage Hand or Warlock's Imp summon which are able to freely be invisible and thus can move about outside of combat to go stand next to an enemy to enable Sneak Attacks)