Brand new 10K MH bulbs yellow

[Jeff]

I have a few brand new 10K bulbs, been on the tank for about two weeks and four weeks now (I staggered them). They are horribly grotesquely yellow in colour. They are much more yellow than the 1 year 10K (same brand) that they are replacing. Picked up from a local store just over a year ago. Bought 4 on boxing day.

Has anyone encountered bad bulbs before?

I'm aware MH bulbs are yellowish when first used until they break in. These are well past any usual break-in phase that I've experienced before.

Could perhaps my ballast be going? Would that affect bulb colour temperature? My ballast is quite old. I've been reef keeping for about 10 years and I still have my original Hamilton dual ballast.

It's really quite bugging me so if anyone has some thoughts I'd appreciate it.

Cheers