When I open a FujiFilm RAW file with 1.4.0 beta it appears in B&W and not in colour. I’m sure they imported in colour with the previous release. If I convert the files to TIFF in Photoshop they then open in colour.
I think you are new to this field. I strongly recommend that you consult our documentation to understand what a CFA image is, what debayering is, and why Siril always opens the image in black and white during the first step.