Its actually a new rule in the NFL where the people who have a green dot get one do-over a quarter, when they use this do-over, the green dot is taken away.

thats how they identify who is wearing the ear piece that listen to the sidelines.

Mono is correct.

The new rule states that one person on each side of the ball will have a headset inside their helmet to hear incoming plays from the sidelines. The earpiece is turned off with 15 seconds left before the end of the time alloted prior to the snap.

mono is correct

it identifys to the officials who is wearing the radio helmet olny one member per team is allowed to wear a Radio Helmet the collor is green because no nfl team wears that shade of green

it's a sissy sticker. It designates who the quarterback is so the defense goes easy on them. i.e. - new NFL sissy quarterback rule.

It's a symbol of wealth. The player with the green sticker is the highest paid player on the team. The new NFL "sissy" rule protects the player with the sticker from being hit too hard. The top paid players are just too valuable to risk injury.