I've done a fe searches, but I can't find the answer I'm looking for. I have a 7th gen Celica with the projectors. When I installed my kit a year ago i took all the glare reduction measures. The beam color has always been strange as noted in the lighting faq because of the projector/reflector design. One solution is to shield the bottom of the bulb. I wwanted to know if adding a strip of say 1200F Barbeque paint to the bulb itself would have an adverse effect. Does anyone know if it will eventual release vapors or chemicals that will harm the bulb?

Applying paint directly to the bulb may shorten its life due to the extra heat. A possible option is to take a thin sheet of aluminum and cut a strip to fit just underneath the bulb. Paint the aluminum strip flat black using any hi-temp paint. You'll have to experiment to find just the right width of the strip so, that it blocks the yellow from hitting the lower part of the reflector without compromising the overall beam pattern. Use JB Weld to attach the aluminum strip directly to base of the bulb but, try to put as much distance between the strip and the return wire. I don't know your exact application so the above may not be feasible but it's just to give you some ideas.

I guess mynext quetion is do you have any idea what the average temp is inside a housing using traditional 35 watt HID technology is. I wa thinking about using a thin sheet of polycarbonate painted with a thin coat of caliper paint inside the housing as a filter. This may work better for the celica application as even the return wire is present in the beam now and a full shield would probably decrease light levels too much

Depending on distance from HID arc and darkness of shield color, expect a temperature between 350-700 degree Celsius. Always use aluminum for shield creations. See http://faq.auto.light.tripod.com/special-topics.htm for more details. Brake caliper paint can be used, just remember to preburn both glue and paint according to "preburning" section on http://faq.auto.light.tripod.com/tools-materials.htm

A possible easier solution to your experiments may lie in an OEM HID projector replacement.