Afterthought...if you have regular LEDs (not made for 12v) you can determine the amount of resistance needed to operate them on 12v by connecting a variable resistor (also known as a potentiometer) with a value of 5K ohms between the LED lead (either + or -) and either ground or the positive 12v source. Usually 1K ohm resistor is good, but if you don't know how your LED was built, you can figure it out with the variable resistor. Simply start at 5K of resistance (all the way to the right or left, depending on which way you connected the variable resistor) and turn slowly until you reach the desired degree of "glow" you want. Use a handheld meter to measure the variable resistor and also to know which resistor value to use when you get your desired brightness. Standard LEDs are not expensive at all (often you can buy 300 for $10 or so) and come in many colors so you could use yellow, orange, red, green, blue, white, purple...lots to choose from here.