The white balancing of which you speak exists but is mearly image manipulation to fool the everyday user into thinking the colours are correct. The colour temperature setting available on many cameras is a similar form of eye-trickery. A finer look at images colour corrected this way will show artifacts such as glints (in terrestrial photography) or stars (in astrophotography) that are not white, or relative colour brightnesses that do not represent the true scene. Using DSP for colour balancing works for everyday consumer level devices but not so much for astronomy. Note that you can not tweak the red colour channel to make a nebula more visible if there is no signal getting through to the sensor from the nebula in the first place. This is very evident in the image by jdbastro of M8. Note how outside the main bright reflection dominated part of the nebula there seems to be simply nothing, just stars. In reality the nebula fades gradually from center to well outside the object. A camera that can see Halpha would pick this fainter nebulosity up, but a camera with a typical commercial IR cut filter will not.