So what I think you’re asking is if the lighting is deferent then the objects should have different lighting. It depends for one can you compare their lighting. Our eye and even some cameras are made to do some adaptation with the lighting. Say you are out side in the sun for an hour and then you walking back inside you will notice the light are dimmer than normal when walking in. If you have a object in the cast shadow and the other out in the open then the one in the cast shadow has to us what little light it can get from the reflected environment as appose to the one out in the sun that is reflecting a large sum of light.
One thing to think about with lighting is it has a max lighting and max dark (the diagram shows that spectrum at the bottom). You do not want to make a painting or drawing that goes from 40%-70% when you can get a lot closer to 0%-100% on lighting. (0% pitch-black – 100% pure and bright white). That is were many young artist and even deviants fail in their graphite drawings they do not have the full spectrum of lighting. Even when you’re in a dark room you have a lighting that would seem relatively high on the value. Not the brightest lighting to be dim. And the same goes for dark not some dull gray on the darker places but rather as black as the medium will allow (graphite is flawed for this but it still can get dark use Ebony pins to get the deepest darks).
That is a good question. I did say that cooler tones are usually a darker cyan blue but that is not all ways the case. It is very common but not a law. One of the spheres is a deep and darker red and that part is the coolest part of that sphere. The light blue on the back of the last sphere is still from a secondary light sources. And it is from reflections second time used (the blue sky). So even if it is not a darker blue it is still a cool tone. The scale at the bottom is to give an idea of the warmest tone to the coolest but it is more dimensional. I hope that answers the question.
As an extension of that, can one assume the inverse if the main light source is cold? I read that if the main light is cold, then the shadows are warm, which means, if this holds, that the reflected light would also be warm.
I do not think that is how it would work if you are in the world of physics. Where did you find this? It may be valid but I would like to read it.
It may work for art in a surreal way and it would be interesting to see. And with artificial lighting as the room may have a dim yellow lighting and a blue bright light. But with natural lighting I am skeptical.
Just say we have a blue sun, they are actually hotter in that the yellow ones (yellow 3000 kelvin blue 8000 kelvin), in our solar system. But the way I imagine it would still work like a prism. And the blue and violet side of the rainbow would still be on the same side as they are turned more that direction. With the sun being blue I would be brighter (like when you drive in the highway at night and being blinded by the blue spot light as apposed to the yellow spot lights, I hate those). But the sky with a blue sun would actually have the cooler part be violet. But that my theory on that matter.
I read the article you showed me and I am not fully convinced. Shadow tones and reflected lighting are from saturated colors reflected from the sky or a surface. One way of thinking about it is if you are on grass some of the reflected light will have a greenish tone. The big reason shadows are blue is the sky is blue and it is reflecting the light. If you are in a white room and the light is a perfect white the objects in the room would be there original hue in both light and shadow.
The paper being crumpled up sound more like another optical affect were the paper will allow some light to pass through. This is like having a yellow window only allowing yellow light in the room. Or even like the blue sky as the light get reflected off the blue sky. Long story short lighting will look more like what chroma it started with, the matter it had to pass though and the matter was reflected off of.
What some artist will do is make the shadow a counter tone to the light side. This helps add contrast to the art work. Contrast is good why to show objects and creating implied lines.
Do you mean 'crevice shadow'? Not just 'folds', but any nooks and crannies, including in one single object. I haven't heard 'crease shadow', although maybe that's just another name for it. (Or the fancy name: ambient occlusion shadow.)