Darktable/Gimp how to fix daylight photos shot with Flash white balance

Processing Play Raw
30

DSC_8957-GIMP-WB1
DSC_8957-GIMP-WB14948×3280 2.86 MB

GIMP and WB
DSC_8957-GIMP-LAB
DSC_8957-GIMP-LAB4948×3280 3.34 MB

GIMP onvert the image to LAB color, choose Colors > Components > Decompose