One head light has yellow hue to it instead of bright white.

What is your question?

One head light of my 2013 XTS has a yellow, or warm white, color instead of the bright white color of the other head light. The lenses are clean/clear. What could be the cause? Both lamps are factory original. The change occurred subtly and within the last few months.

How long has your 2013 Cadillac XTS had this problem?

A few weeks