Mass tone (mass color): According to ASTM, when viewed by reflected light, the color of a pigment-vehicle mixture of a thickness that completely obscures the background is known as mass tone or mass color.
Tint color (reduced color): The color produced by mixing a predominant amount of a white pigment (generally titanium dioxide) with a colored pigment is known as tint color or reduced color.
Pigment suppliers typically provide chips of mass tone and tint colors (with two or three different levels of reduction in their technical bulletins.