I agree that for artistic purpose you may not want perfect chromatic adaptation in all cases. There are several photographers that use colored gels over flashes to get particular color effects (Joe McNally comes to mind).
Also, you may have images with different illuminants (like the examples of the inside of the house with an incandescent light and the outside at sunlight) and in these cases, the possibility of selecting different areas with different white balance each looks really interesting.
The part which I fail to grasp is about how to involve different color spaces here. All of the above we can handle today either with color filters over lights (whenever possible) or by blending layers in photoshop (time consuming) but working always in one color space, being AdobeRGB or PhotoshopRGB.
Some possibilities:
- Current color management is not flexible enough as is today and you will have compromises where you loose some saturated colors. An option might be to use the color space that will preserve the saturated colors that interest you as the author of the image (may be that R=G=B is not neutral).
- The possibility to define adaptive color spaces depending on scene content and photographers artistic´s purposes (might be a nightmare to implement)
- Raw converters that allow to select not only different white balance but different color spaces for selected areas of an image. I don´t even know if this make sense or is feasible. I was just thinking in the old days of the darkroom, specifically B&W. Suppose you had a part of the image with normal to high contrast and another with very low contrast, with single graded paper you made compromises, with multigrade paper, you could print different parts of the image with different contrast
These are just ideas that come to mind,