Don't remember the temp now, but my lights were a bright white with a slight tinge of blue. They've been in service for about a year and a half now and headlights are on a lot in this part of the World. The left one now is showing a definite reddish tint and is much less bright. How does a failing bulb present? I suppose the simplest way to see if it is bulb or ballast is to just swap bulbs? Any experience? Thoughts?