This is green:
In the above screenshot no white balance multipliers have been applied to the target chart shot. In fact I disabled the white balance module. The same green result is obtained by setting the white balance multipliers to 1,1,1. I assigned the camera input profile and also asked for the file to be output still in the camera input profile. The screenshot (taken using GIMP) has been converted from the monitor profile to sRGB, but what you see on the screen is what the file looks like after the camera input profile has been applied.
The image in darktable - which is ICC profile color-managed - is using the same monitor profile to show the image as GIMP assigned to the screenshot before converting the screenshot to sRGB. The screenshot and the image in darktable look the same. This is green. There is no trickery here, no slight of hand using “lights” - it really is green.
On the other hand, this is not green, even though I used the same darktable parameters as for the above target chart screenshot, that is, the white balance module is disabled:
The reason the image in the above screenshot shows no green bias is because I removed the green bias by putting a heavy magenta filter - a real, actual physical filter - in front of the lens before taking the photograph.
If there is no green bias in a raw file, how is it that putting a physical magenta filter in front of the lens does in fact remove a green bias?