kinda late to the party but I have had very good luck using Duplicolor Metalcast Yellow paint on lenses to change the color. This way I'm not sacrificing light output by getting a junk yellow bulb.
I am not avoiding yellow blubs as they do NOT decrease light output, Spraying and effectively ruining your lights by painting them do decrease light output. I see one of the 10 commandments here. THOU SHAW DECREASE LIGHT OUTPUT WHENEVER POSSIBLE. REGARD FOR YOUR SAFETY IS NOT NEEDED.