Brittle wires in recessed can light
The color really is not a concern in US residential wiring. Well if it is listed and properly installed. 
Halogen lighting will get hot but a UL listed fixture for homes in the US would be limited to 20 amps and the fixture wiring to the lamp would be a special type of wire that would be ok with #12 Romex to the junction box. No matter what size or color feed ,,, white,, yellow or orange with todays cable colors of the fixture was listed for the wire size (usually white 15 amp) and UL listed brittle wires is not a problem. Orange or 10 gauge is good for 30 amps. This is what most water heaters and dryers run on. 

Ok ,,, ok , I know I am getting long here but a UL listed fixture won’t have the problems when properly installed so is it a ? ?? Product or a miswired install???? The fixture should have a junction box where the Romex connects to the fixture wire(this wire can take the heat)  ... if not UL listed with proper connections get ready for failure of the fixture, because 10 awg wiring can drive a 10kw lamp at my plant that on a 50’ pole will light the infield of a baseball with out getting warm.  Ok not halogen but a listed fixture properly installed only needs a white cable on a 15 amp breaker,,, nnnot listed good luck if you have a fire.
 + + to Isherwood for white 15 &amp; orange 30.