I used a HDR image to serve as the background light. It was found that the lighting effect is too “white” and made the rendered image a little bit 'blue" and does not give a warm effect.
I want to make the white light a little bit yellow to resemble the natural sun light.
How can we modify the light colour in Cycle World shader node?
Use RGB Curves node, or mixRGB, or Hue Saturation.
As being said, you can attach different image altering nodes in the shader editor. Switch from object to world. Remember there are different color spaces and the rendering is also done in a certain colorspace that alter the look. So the color and whitepoint transformation render setting is a part you wanna look into.
The HDRI quality has a role too, a 32bit one will give you a lot of options for exposure.
The color play of sun & sky will vary according to haze, clouds, and sun elevation. But often HDRs are adjusted to be more neutral to white overall. However, the color distance between the sun and sky should be correct.
With that in mind, I think the correct procedure is to use a coloring addon (I use Photographer, good enough) and check against real photos set to some neutral’ish (5500K-6500K should be ok) color balance on the camera and set Photographer addons color balance to same. Now adjust the colors of the HDR to be approximately the same in Blender as in the photo.
You now have set a reference. If you now do indoor lighting and WB for 2700-3000K lights (making them neutral white), you adjust Photographer addons white balance and the blue sky outdoor will become even bluer.
This is what the camera and eyes will see. However, your brain plays tricks on you and outdoor and indoor will appear to be much closer together. And it is an effect photographer don’t like at all, making them flash a site with close-to-outdoor WB flashes to balance out the WB (and lighting as well). But we’re lucky - we just lower the effect slider of the HDR coloring RGB Mix node. Here a real photo, just to illustrate how “blue” the outside really is when it’s dimmed down (late morning) and overcast (no sun, so more blue), when the cameras WB is set to indoor. If camera WB was set to overcast, the outdoor would go more toward neutral but the indoor lighting would get extremely yellow.
Thank you all for the valuable advices.
I have tried the “Adding mixRGB” cycle node approach and find the following node setup can achieve the desired result by reducing the Blue component of ray. The colour of HDR sky seems didn’t affected and the scene become a little bit more yellowish.
The nodes setup may not be totally correct but it is able to modify the ray colour to some extent.
