Every skin tone of an emoji

Where the modifier actually goes

A skin tone is its own character, appended to the emoji it applies to. On a simple emoji that is the end of the string. On a joined sequence it is not: 👩‍🚀 is a woman, a joiner and a rocket, and the tone belongs to the woman — so it goes after her and before the joiner. Append it to the end instead and you have written "astronaut, then a color swatch", which is what a reader will see.

Not every emoji takes one. The modifier only applies to emoji that show human skin, and adding it to 🚀 or 🎉 produces the emoji followed by a visible brown square. The buttons above are disabled for those, rather than handing you a string that looks broken everywhere you paste it. The Unicode inspector shows the same thing from the other side, character by character.