I have dealt with resistors quite a bit as an electrician. We use them a lot in fire alarm installations and control circuits. I've only ever known them to use the color bands to represent their resistive value. I need a little more info though as to what you are trying to accomplish. I'm assuming that your blower motor is not rated for the voltage or amperage that your power supply is putting out and your trying to bump down what you are delivering to the motor. What is the output of the power supply, what is your desired load to the motor, and what is the circuit AC or DC?