Abstract: A method for changing color of orchids comprises the steps of: first, forming a housing space in a stalk of a plant; and second, providing a solid dye smaller than the diameter of the stalk and dispensing the solid dye via a suction means into the housing space. Water is supplied to the plant before or after the solid dye is dispensed to dissolve the solid dye to facilitate absorption. Thus the color of the petals of the plant can be changed quickly and evenly. Diversified and brilliant colors can be formed on the petals through the simple dyeing process.