Color Theory question.

JordanN

I don't know where else to ask this so I'll try here.

So lately I've noticed white objects tend to have the brightest value in any picture. Whether it's at morning or night, a white object's surface will be the most visible. Makes sense right since white is suppose to contain all the colors.


So now at the same time, I want to know what comes next? What I mean is, since white objects shines the brightest, what are next colors in ranking order that appear brightest in light and then darkest?

For example, is red a brighter color than green? Or is saturated beige more brighter than turquoise etc etc.

ZacD

JordanN

Thanks for the quick reply! This will help me very much with my next work.

Gestalt

If you want a quick way to work with colors that appear to be about the same lightness to your eye there are some color spaces that are based around perception.

The Lab color space has three components, L for lightness and two variables a and b for the chroma/hue.
http://en.wikipedia.org/wiki/Lab_color_space

Relative luminance is based on the luminosity functions for the cones in the eye.
http://en.wikipedia.org/wiki/Luminosity_function

kurt_hectic

That's the topic I've tried to know better some time ago. I still don't know how it works.

I'm talking about this technique to start with grayscale image and then colouring it.
Because Hue changes Brightness it's all become messed up...

Are people just ignore these facts and adjust images on each step or use some super advanced tricks? (to predict brightness changes made by hue)

JordanN

Since this thread is still active, I got another question.

I'm trying to understand global illumination but I'm getting two conflicting answers. In my book "Understanding Color. An Introduction For Designers" it says when light from a green wall hits a chicken with red feathers, the feathers become more dark red. But then I saw this video where the color of spheres bleeds into the yellow wall (and it looks brighter).

Does the color from the indirect bounces get brighter or darker? Also, shouldn't that color blend? For example, take these two spheres (one red and one green).
Does the red light from the sphere turn a sort of orange on the green sphere (because red and green mixed together make yellow)?




Also related, what happens when you have multi-colored lights? Does the specular highlight blend in with the object's surface you are trying to light or does it remain the same as the original light source's color?

Gestalt

Indirect lighting is adding more light but different materials are able to absorb different wavelengths (which is what gives them the appearance of having a specific color; for example: if a material were to absorb all wavelengths except for the red ones, it would appear red because it is only giving off those red wavelengths).

So theoretically, depending on the wavelengths present in the indirect light, a surface will become brighter based on how much of those wavelengths it doesn't absorb.

If the indirect light is red and made of red wavelengths, and if the second surface absorbs those wavelengths, then you will not notice the bounced light as much (because the surface absorbs it).

Bounced lighting won't make a surface 'darker' than with just the direct lighting but it could change the color we perceive.

On another note, the 'lighter/darker' distinction is tricky if we're talking about something like painting a realistic picture because we perceive certain colors as being lighter or darker than other ones but that doesn't refer to the actual intensity of the light, it refers to our perception of those colors (how our eyes respond to the color).