In photographing indoors, especially bands with all the different colored lights, you need to work on white balance in post processing. In the Digital Photography world, almost all photographs need to be color corrected and white balanced with software in post processing.
Understanding White Balance
If you come from the world of films, you may remember using filters to correct for incandescent or fluorescent lighting. Most people don’t bother and their indoors pictures invariably come out with a yellow/orange or bluish cast. In the digital world, these correction filters are no longer necessary, replaced by a feature found in most — even the entry-level — digital cameras called, “White Balance.”
Light Color Temperature
The reason that pictures turn out with a yellow/orange cast in incandescent (tungsten) lighting and bluish in fluorescent lighting is because light has a color temperature. A low color temperature shifts light toward the red; a high color temperature shifts light toward the blue. Different light sources emit light at different color temperatures, and thus the color cast.
By using an orange or blue filter, we absorb the orange and blue light to correct for the “imbalance” — the net effect is a shift in the color temperature.
In digital photography, we can simply tell the image sensor to do that color shift for us. But how do we know in which direction of the color temperature to shift, and by how much?
Manual White Balance
This is where the concept of “White Balance” comes in. If we can tell the camera which object in the room is white and supposed to come out white in the picture, the camera can calculate the difference between the current color temperature of that object and the correct color temperature of a white object. And then shift all colours by that difference.
Most advanced digital cameras therefore provide the feature to manually set the white balance.
By pointing the camera at a white or gray card (angled so that it is reflecting light from the room) as a neutral reference, filling the screen completely with it, then pressing the White Balance button (or set it in the menu), the camera does its WB calculation.
From then on, any picture taken will have its color temperature shifted appropriately. It’s quite simple, really, and you should not be afraid to try it out and see your indoors pictures improve considerably (assuming there is enough light for correct exposure).
[A "neutral" gray is 18% gray and will reflect all colors equally.]
One product that is very helpful in post processing for white balance and color balance is The Color Checker Passport, made by X-Rite.