What a skin tone modifier actually is

Skin tone options are a separate character that combines with a base person or hand emoji to change its displayed color, based on the Fitzpatrick scale used in dermatology to describe a range of skin tones.

How to choose one

On most phones, press and hold a person or hand emoji in the picker to bring up a row of skin tone options, then tap the one you want; it becomes your default for that emoji going forward on many keyboards.

Why not every emoji has this option

Only emoji that depict a person or a body part support skin tone modifiers — objects, animals, and food emoji don't have this option since there's no skin tone involved.

What happens if a modifier isn't supported

If you send a modified emoji to someone on an older device or app that doesn't support skin tone modifiers, it may display as the base yellow emoji plus a separate colored square, rather than blending into one image.