Abstract: An apparatus and method for the modification of the color of television pictures in arbitrarily selected regions of the color space and of the picture. A region within which color modification is to take place is defined by establishing the bounds, or limits for the region. Apparatus is described by which a determination can be made whether any given picture element lies within the region. For those picture elements which lie within the region, modification voltages are added to the television signals to accomplish the desired color modifications. Display apparatus is described which facilitates setting of proper bounds for the color modification region.