I'll try to find the article, but it points out the sole purpose of bias lighting, to reduce eye strain. 6500k at 250 lumens. That color temp and output also blends with a properly calibrated tv. If colored bias is used it degragates the image. Any wall painted with a color, be it blue red or so on, will cast a hue around the tv which is why a grey wall works (also think silver screen for a projector, ideally a pj screen is grey or 'silver')