I found a post on a BMW forum about camouflaging a yellow turn signal bulb on clear aftermarket taillights. This process makes it were you don't notice the bulb, but it still lights up yellow....just with 1/2 to 3/4 the intensity.

I did this to the front turn signal bulbs on my Sonata and it looks awesome!!! I would suggest this to anyone with clear lenses that don't what to those yellow bulbs.

All you do is:
1) Take the bulb out
2) Spray paint the bulb heads (not the metal connector end, of course) with silver metallic paint. I used duplicolor paint that I had laying around. Spray about 3 coats on until the yellow isn't noticable.
3) Let the paint dry
4) Reinstall the bulb

That's it. It takes less than 15 minutes to do both bulbs...and most of that time is drying time.

Here is a link to what it does for the taillights of a BMW with frosted-clear lenses. On the Sonata, the lenses aren't frosted, just clear so it is even more dramatic.
www.apexcone.com/JimPowellHomepage/TechProcedures/SilverLamps/SilverLamps.html

Here is a better solution replace the entire bulb with a clear amber emitting led bulb and the lens is clear in all directions. And it looks better is faster in speed is more noticeable in all lights and it's easy to change without spraying the bulb's which in turn the paint will heat up and disentegrate off the bulb, may be even making a mess inside the lens. The solution is LED technology.

or buy the sylvania silverstar bulbs $20 for two (pricey) but the bulbs are blue and they light up amber.

spraying it is kinda sketchy...