Before you do anything, live with the existing new bulb a week or two. MH bulbs often shift color somewhat while new. However, usually the shift is toward yellow from blue. Still, considering that MH bulbs cost about $70 up, you don't want to casually replace them.
The following is my opinion, and this is very subjective. I didn't make any actual measurements. These are all 250w bulbs, so the 175w bulbs may be different. Also, keep in mind that many bulbs come from the same source, and are simply labelled for the brand.
I found 15000K XM bulbs to be sort of a violet compared to blue.
I found 14500K Gieseman bulbs to be nice, but expensive.
I found 14000K Phoenix bulbs to be good, and a little less expensive than average.
I found 14000K Hamilton bulbs to be good. I have not experienced the problem of premature burn out that some people have reported. I'm using these now.
I found 10000K Aqualine bulbs to have a bit more blue than your typical 10000K bulb, but they are also expensive.
I also highly recommend Sanjay Joshi's reef lighting guide (offsite,new location) -
Manhattan Reefs - Sanjay's Lighting Guide
You will be able to see actual spectrum plots of most bulbs and commonly used ballasts available on that site. You can go through the bulbs and choose one that has more blue in it. This will give you much better information that anything subjective that may be written here.
Keep in mind that when you evaluate a bulb, you must consider the entire color spectrum. A bulb can look blue either because the amount of blue light is higher or because the rest of the color spectrum is lower. You usually want the former.
