0AndyGadgetBest Answer 8 years ago ReplyUpvoteTo get the maximum range of brightness, work out what value resistor you'd need for each colour LED from the voltage drop (Vf) and maximum current (Ifmax) - There's a calculator HERE. You'll also need to enter the supply voltage you're running from. You need the resistors in the circuit to limit the current in the minimum pot position and prevent damage to the LED. Use 250R (or 500R) pots and connect the centre pin to one of the end pins. Now wire the relevant LED and resistor to this so you've got the pot, the resistor and the LED in series. Do this for the other 2 LEDs and then wire each of these circuits across the supply. You can now adjust each LED over the full range of brightness without fear of damaging it.