I use 10 000k 175w ushio bulbs supplemented with a 95W VHO actinic on my tank.
Here's a pic of my xenia patch before the bulbs were burned in:
As you can see, its pretty yellow even with the 95W actinic.
Here's a pic of the same xenia patch after the bulbs were burned in:
Quite an improvement in colour IMO.
Both pictures were taken with the same camera on the same setting.
-Richer