Ur kinda right, you dont exactly have to tell the camera what white is you just have to calibrate it for the light you are shooting in at the time. Most of the time this is done by simply shooting a grey card in the same light as your shooting in. A grey card is just a piece of card board colored grey with 18% reflectance across the visible spectrum. Select the picture with grey card in it and use ur "eval" function on the gray card and its set. Doing this will set ur white balance and correct the color for all the shots in that shoot. For his shoot he should of just changed his white balance to one of the preset white balance setting like tungsten, fluorescent, and daylight. For those pictures tungsten is what you should have used. Another thing for shooting at night, if you dont have a tripod never go lower than 1/125sec for hand held, also try raising ur ISO (film speed) as high as you can without getting a lot of noise and sacrificing quality.