About 15-16 years ago, I was given a PHILIPS 250w  

 lamp, but the catalog number had an extra character at the end.  The Utility company who serviced us on the MS Gulf Coast was a Touchstone Energy Co. Singing River Electric Power Association.  They generally used PHILIPS lamps, and Fisher Pierce PE Controls (sometimes, they used LAMPAS, Area Lighting Research, and believe it or not, I got my particular office to try DTL for the first time, but they used Fisher Pierce 90% of the time).  One day, one of the journeymen gave me a lamp that instead of being marked with the standard C250S50 was marked witb 
C250S50/C.  I found out the extra C stood for Comfort.  Well, I tried it out in my GE M250-R2, and I didn't notice any difference in the color temperature at all.  Having done a little research, I have determined that this particular lamp -SHOULD- have more of a higher color temp, to be a little whiter.  The ceramic arc tube is a tad bit shorter than the standard C250S50 arc tube.  So can anyone explain this to me?  I am frankly stumped.