In color theory, what is a color plus white called?

When you’re looking for a color that is lighter than a pure hue, this is achieved by adding white. When white is added to a hue, it is known as a tint. When you take red, for example, adding white will make the color a lighter version of red. Many refer to this as reducing a color’s brightness, but the brightness actually remains the same.

Source: Integrity Painting