Rugs can be transformed by the application of dyes via rug over dyeing or custom color dyeing.  

Rug over dyeing (overdyeing) is simply the application of a standard color, such as a fuchsia or cyan or red. 

A custom color match on the other hand is a specialized type of Rug Over dyeing, where the dyer matches a rug to a specific color or object of the client's choosing, by calculating the exact color that needs to be added to the rug.