I've been running both 250w DE 10K and 250w SE 10K for about 4 weeks now and here are my observations.
The SE, on an electronic EVC ballast, burned a really garish pink in the beginning. Only in the last few days have I noticed the shift towards a crisper white color.
The DE, on Aquamedic HQI ballast, has always been a white/blue color but it doesn't appear to be as bright as the SE - at least to my eyes. So, this part actually seems consistent with what Steve noticed in terms of brightness.
HTH
The SE, on an electronic EVC ballast, burned a really garish pink in the beginning. Only in the last few days have I noticed the shift towards a crisper white color.
The DE, on Aquamedic HQI ballast, has always been a white/blue color but it doesn't appear to be as bright as the SE - at least to my eyes. So, this part actually seems consistent with what Steve noticed in terms of brightness.
HTH