The document provides instructions to color code cars in a line based on their position. It tells the reader to color the 2nd car blue, the 4th car yellow, the 19th car red, and to color the 15th, 18th, 3rd, 5th and 13th cars brown. It also instructs coloring the 1st, 9th, 11th, 14th, and 20th cars green.