resistor's values are rated by the colors that are painted on the resistor. the colored bands that are used on the sides of a resistor are black, brown, red, orange, yellow, green, blue, purple, gray, and white. each color represents a different number. the black band represents the number 0, brown band represents the number 1, red is 2 and so on all the way to white which is the number 9. these numbers are very important in the electronic field.