Download colcod color code resistor capacitor, Colcod is a program with a graphical interface that displays the color coding on resistors with 4 or 5 color bands if you enter a value. For resistors with 4 color bands (the most common kind), entering a value will display the nearest standard value in the E12 series and the corresponding color code. Inversely, clicking on the colors of an unknown resistor or capacitor will display value, tolerance and maximum working voltage (capacitors).
Hi Adam, You can connect a 12 or 18V DC source in the power connector, do not worry about polarity.