Lighting equations and color

Every beginner tutorial I’ve seen so far does something like this:

Color of pixel = Color of material * (whatever BDRF and attenuation functions) * intensity of light
So let’s say I had a pure blue material, RGB: [0, 0, 255].
If I put a really intense white light next to it, the color of the pixel ends up being [0, 0, 255].

But in real life, I took a bright white light very close to a blue piece of paper. The paper appears white, not solid, bright blue.

Also, let’s say I have a pure red colored light RGB: [255, 0, 0], and I have a material that’s purely blue, as in RGB: [0, 0, 255].

I tried putting a red light next to a blue piece of paper. When the light is very close, the paper appears red. If I move the light a bit away, the paper actually appears purple (red + blue = purple, makes sense).

What kind of lighting model accounts for these kinds of phenomena?

What kind of lighting model accounts for these kinds of phenomena?

The kind where you use accurate inputs :wink:

In reality, there’s no such thing as zero reflectance. So the blue paper in your example is not [0, 0, 255].

Also, consider that most materials are colourless (white) when it comes to specular reflection. Coloured materials typically consist of diffuse-reflecting coloured particles suspended within a colourless specular-reflecting medium.