Hi Richie,
Wow ... I am slightly overwhelmed with such a lot of test pictures, thinking and questions.
Another problem is, that I am unfortunately NO expert in colour spaces ...well ... we will have to wait for REDFOX, who knows much more in this field.
If someone else feels more firm with colour spaces ... tehey are invited to answer!
Well, as a first aid, I will dare an answer .... but well ... as I indicated above ...
You might know this for general information?!
The most common and best supported colour space is sRGB. Our monitors, printers, internet browsers and most image-processing software cope with it best.
Therefore, I always save my work on sRGB. It might be sensible to go for other colour spaces to have more "image material" for image processing.
However .... not my ground!
White Balancing:
Again: The overall target of any white-balancing activities is, that any "paperwhite" objects in the scene really are recorded white without any shifts (tints) in colours.
The issue is endless ... there are quite a number of scenes, in which NO white balance really works ... I will show you an example below.
AWB, for instance, often works well. As long as the the total sum of all colours in a scene equals some neutral grey, it will work perfectly.
If your scene is unbalanced (in terms of colour distribution) it will certainly fail.
As a word of comfort .....
SIGMA X3F-RAWs always contain the complete colour information no matter whether the camera gets it wrong.
If you know "your" colours, you can always fix it on your computer.
I think, this is a good link on the issue.
Well .... some pictures do not allow any white balance. In this case, the scene itself is not illuminated ... it shines directly ... so no grey card can help. Just do it they way you like it!
See you with nice pictures
Klaus