blue's waaay too dark. i put two on each because without it it's so teal it looks almost green, but i think that's because of the yellow tinge of the incandecent bulbs. i'm going to order some LEDs if the red bulb covers don't make it significantly brighter.
don't get me wrong, it's doable, but waaay too faint for my tastes. especially the needles.
i'll be trying red, but if that doesn't work i'll be going way of LED.