Auto WB usually tries to adjust the color of something close to white to make it exactly white. You can do this manually by using the eyedropper tool (DT must have something similar) to choose a white area as a reference—e.g. white portions of the wall lit by direct sun. You could also try areas that are a neutral gray (some rocks) or close to black. The critical thing is that they have to be neutral—no color—and not completely white or black.

@brook I have minimal experience in Darktable but lots in Lightroom.

First thing: check your color balance. Try an auto WB in DT to see if it matches the camera. Since this was shot in daylight, next try starting with a daylight preset, and move the temperature toward yellow until you get close. Then adjust the tint toward magenta until you get the color you want—you should be able to get pretty close to the camera setting. One you've set the overall color, you can tweak the look of the sky.