COLORANT is a term used to describe any substance that can be used to impart color to a material. TONER is a powder or liquid used in photocopying and laser printing to produce a colored image. DYE is a colored substance that has an affinity for the material to which it is applied. ETHYLENE is a colorless, flammable gas with a sweet odor that is used in the production of polyethylene plastics. EOSIN is a red DYE used in histology and microscopy to STAIN tissue sections. STAIN is a DYE or chemical used to color or discolor a material or object. All of these terms are related to the term COLORANT, as they all refer to substances used to impart color to a material.