Emoji characters can be modified to use one of five different skin tone modifiers. Each tone is based on the Fitzpatrick Scale.

An Emoji Modifier Sequence is created automatically when a modifier character is inserted after a supported base emoji character, resulting in a single emoji with skin tone.

Many emojis with skin tones are Emoji ZWJ Sequences, due to the presence of additional characters for gender, multiple people, or a combination of people and objects.