Light frames coming out gray after calibration?

[mostlyemptyspace]

I'm new to PixInsight. This is my first time trying to do stacking in PI. Normally I use DSS. I imaged M42 the other night, with 120 light frames, 200 bias frames, 70 darks, and 70 flats.
I ran through the BatchPreprocessing script, and for some reason all of the calibrated frames came out in grayscale. If I calibrate manually using ImageCalibration, they come out in RGB. What am I doing wrong?

[cdesselles]

Are you using RAW files from a DSLR?  If so, make sure you select CFA to have the BPP script automatically debayer the frames.