There are several colors of concealer, each serving a different purpose.
Blue concealer: Used for women with dull, pale skin; a thin layer of blue concealer is applied followed by a layer of beige concealer.
Yellow concealer: Used for brightening women with darker skin; it is applied under the eyes and above the cheekbone.
Purple concealer: Used to cover dark spots, freckles, and melasma; it is applied only to the affected area.
Pink concealer: Specifically used for fair skin to counteract the white tone.
Orange concealer: Used to brighten the entire face if it is dark, and it’s also used to lighten the under-eye area; orange concealer is applied first, followed by beige.
Green concealer: Applied to pink or red spots to conceal blemishes and pimples.
Brown concealer: Used for contouring the skin.
As for blending concealers, mixing blue with yellow will produce green, blending blue with red will produce purple, and combining red with yellow will result in orange.