6500 Kelvin ≠ white?

[Alex_M]

There's something that's been bugging me for quite a while. I've set my camera white balance to 6500K, lights are white and material is grey but the rendered image gets a pink color cast. Why is that? Shouldn't 6500K result in neutral grey colors?

Please check the attached screenshot:



However, if I set the camera white balance to "Custom" and chose white color, I do get grey colors. The closer I could get to neutral white with Kelvin adjustment is when I set the camera to 5600K but it still isn't neutral - it's got a bit of purple tint. It just seems that you can never get neutral color with Kelvin adjustment in the camera and white lights and materials. You either get a bit of blue cast or a bit of red cast in the rendering but never neutral white. Is this normal?

[WilleViz]

Hmmm. Interesting. In photography you have to balance both the white temperature between yellow and blue and the tint between green/magenta cast, but normally a preset for 6500K wont apply any tint in my experience. But it does seem to apply a bit of magenta cast here.

6500K is a bit to the cold/blue side in itself, and I think that the best option is to indeed choose a neutral (as in a pure White color) and add wanted color cast like a bit more warm or cold with the lights. Unless you really want an overall more warm or cold tone.

This doesn't really answer you question though.

[joconnell]

Yep - 6500k is slightly blueish, more like daylight. So if your light source is tinting everything blue, the white balance adds in warm tones to cancel it out. From what you say your light sources are all white though so there's no blue to cancel out, hence the magenta showing itself. If your lights used temperature instead of colour and they were set to 6500k, you'd get grey materials again since there'd be enough blue for the magenta to cancel out.

[WilleViz]

Oh, one more thing. The magenta color cast is probably from the light outside.

Edit: Listen to joconnell instead!

[Alex_M]

Got it, thanks! 6500 is indeed not white. After trying what joconnell suggested, (setting my lights to 6500k) things balance out and I get neutral colors.