I went through a ton of different pnp led bulbs to find ones that were bright enough to use in my 3rd brake light. This style led was just as bright as the incandescent bulb it replaced. http://www.ebay.com/itm/2pcs-of-T10-Wedge-LED-Trunk-Cargo-Light-9-Flux-Red-Light-Bulbs-One-Pair-2825-/191205357799?pt=Motors_Car_Truck_Parts_Accessories&hash=item2c84ba38e7&vxp=mtr
And oldschool is absolutely correct about wanting to use the same color led as the lens they're shining through. Long story short, leds don't produce the entire light spectrum like incandescents do, so for example a white led produces almost no red light to make it through the lens.