Which of these is the practice of applying color to a solid surface?

Painting is a visual art, which is characterized by the practice of applying paint, pigment, color, or other medium to a solid surface (called "matrix" or "support"). The medium is commonly applied to the base with a brush, but other implements, such as knives, sponges, and airbrushes, may be used. One who produces paintings is called a painter.

Source: Wikipedia