Hello

First of all excuse my bad english

Difficult to provide a precise answer when the question leaves uncertainties hanging.

In summary your analysis of the operating principle of Ciecam is fairly correct. We take into account “scene conditions” to calculate a position in a some form of work profile (with a small gamut)

In this “space” we can make modifications which will take into account the physiological principles of men (their brain, their eye) and not only on mathematical principles.

After, we can take into account the “viewing conditions”.

It is (I suppose to simplify), in your case the variation of “illuminant” which will lead to a change in the appearance of the image.

In fact you can “warm” or “cool” the image, regardless of other possible arguments that are important (surround scene and viewing, mean luminance Yb scene and viewing, absolute luminance scene and wiewing);

But for this to work, I am not “god” and I do not work miracles, it is necessary that certain prerequisites of ciecam are respected in particular that the illuminants are with a CRI (color renderind index) close to 100, that there are no multiple illuminants, neither reflections, nor too restrictive luminance conditions. For more information see rawpedia

https://rawpedia.rawtherapee.com/CIECAM02/fr

First of all, the white balance “scene” must be correct (CRI, etc.), and in limits of daylight illumiant (about 4100K to 10000K) under we can use blackbody, and above be carefull.

As a reminder a color (for each pixel) will be perceived by the result of a mathematical formula

Matrix spectral Color_percept pixel_xy = Matrix spectral illuminant (T - g) * Matrix spectral color pixel_xy / Matrix standard observer 2°

After that, it is necessary - in all cases to make a chromatic adaptation - to take into account our brain and eyes.

Remark: grey white balance, or pick on a neutral patch, does not necessarily give the right answer, contrary to popular belief.

In particular “pick” which can only work with small temperature differences, otherwise we infer a linear tansformation, which will probably give erroneous results for colors with strong saturation.

I recommand to use “Itcwb” if possible(Iterative temperature white balance),with an algorithm that I developed (actually in branch “autowb”). This algorithm compare a number of image colors (20 to 40), with reference colors known from 200.

It calculate first green (green magenta) which is at least as important as “red blue”, by an iterative approach which optimizes the correlation (Student)

If I suppose, WB is correct, you can change the appearance with 3 ways (using ciecam principles)

- use principal module Ciecam with “free temp + green + cat02” and the value you want in viewing conditions (warm or cool)
- use branch cat0WB, which realize the same thing, but suppose viewng conditions are D50
- une branch newlocallab, and use “warm - cool” which will take into account the initial image

But nothing prevents you from using tools like tone-mapping or color-toning afterwards to create special effects

jacques