I would recommend you all wear the same style and colour tones/shades. However if you all wear the same colour (eg. all in black or white) your bodies will blend together, so I would avoid that.

I always find dressing to suit your house helps too. For example if you plan on putting the photos in the lounge room and your colour palette in the lounge room is black and silver, then I would wear shades of grey, black and white. IYKWIM. You wouldn't want everyone in pink, it would look out of place.

As someone mentioned above blue's are great. Especially when mixed with white and little red.