The colour portion of the ink which may be pigment or dye or a combination of the two.

Any dye colour or pigment or concentrate that may be added to a liquid surface coating in order to impart a colour to that coating i.e. tinting.

A colourant is something added to something else to cause a change in colour. Colourants can be dyes, pigments, inks, paint, or chemicals. For example, this could be adding white to tint a paint, or black to shade a paint, ultimately changing the colour or value.