Many years ago, Lego bricks came in only three colors, red, yellow and blue. Until 1958, when the LEGO Group applied for a patent for the design of bumps and tube grooves, there were only 7 colors at that time, white, black, red, blue, yellow, green and transparent. Now Lego particles have richer colors, dark green, green, light blue, dark gray, bright orange, pink. Because of the limitations of the color of Lego particles, and the challenges of using color in the Lego system.