I wanted my Autometer gauges to be backlit in blue to match the rest of my interior. I tried the blue bulb 'condoms' that Autometer sells, but they were useless. They blocked too much of the light so that I could hardly read the gauges at night, and the light that did get through looked green. I bought some 4 LED 194 type bulbs from eBay to try them out. Here is what the contestants look like:
And here is a not so great pic that shows the result:
The LED bulb is on the top gauge (duh) and yes the bottom gauge is lit. Clearly the LED bulb is much brighter and actually looks blue. They are a little costly, but they look really nice and will probably last longer than your car will.

And here is a not so great pic that shows the result:

The LED bulb is on the top gauge (duh) and yes the bottom gauge is lit. Clearly the LED bulb is much brighter and actually looks blue. They are a little costly, but they look really nice and will probably last longer than your car will.