When manufactures assemble torsion springs (Torsion springs are tubular and attach to metal pole above door opening) they have to mark them in two different ways. They do this by color coding. Springs are made as a left hand wind and right hand wind. Left spring is painted red at the very end of the spring. Right side spring is painted black at the end of the spring.

The color that torsion springs have

The other color that torsion springs have painted on them represents the wire gauge or wire thickness. This color is there so technicians can just look at a spring and know what wire size it is without using a wire gauge or other methods to determine the wire size. These colors are painted directly on the spring wire, not on the ends where the screws are located on the springs.

The other markings on the torsion spring are a straight line all the way across spring. This line also has the spring size printed on it as well. The straight line is only visible when spring is unwound. When you wind the spring 1 revolution the line becomes diagonal and every revolution will add another diagonal line. This lets you know how many winds the spring has on it by counting the diagonal lines.

The paint on the spring

The paint on the spring is important because the bigger the wire size means the stronger the power of the spring will be. Also the red or black paint is there just to let technicians identify left or right quickly. Any parts on a garage door the have a left or right will have red or black painted on it.