Princeton Tec Quad – bluish white or white beam?

It's a cold white beam with purple fringe typical of 5mm white LEDs. I don't know what the Kelvin measurement might be, but I'll venture a guess it's daylight-range or higher.

LED bin variations make a definitve answer even tougher, although I don't think it's as much an issue with these LEDs as it is with the 1-watt and higher types.

It's a good question, but the answer is more complex.
The LED chip in a 'white LED' emits blue light. The phosphor on the LED chip converts some of that to yellow light. The two can be balanced to look sort-of white.
But you may find the reds in your photos are a bit dull as the 'white LED' does not emit much energy in the significant red region. Skin colour may not look quite right.
(I tried using them for medical diagnostics, and this was a problem.)

cheers

Thanks Rick and Roger, good info and all good points. I'm thinking it will probably be OK augmenting the flash for general purpose low light photography. I think the photo device I found here which gave me the idea uses vanilla-tinted LEDs, though I've never checked it out live:

CameraBright X1-R Digital/Video Camera Light (Silver)
http://www.bhphotovideo.com/c/product/385700-REG/CameraBright_CBX1_X1_R_Digital_Video_Camera_Light.html

My regular headlamp is a modified EOS that uses a vanilla tinted Seoul P4 LED and a reflector which puts out powerful throw/punch + a good flood (unlike the EOS optic which has only throw/punch and no flood). The Vanilla tint throws a more natural warm light than bluish-white LEDs.

For photography the vanilla tint would probably be better than bluish white on the Quad, but my modded EOS beam is too strong to point at people's faces (who needs to worry about red eye when no one can keep their eyes open?). I'll look into whether I can get vanilla-tinted LEDs at low cost for the Quad, or get a light like it.