Know-How? Pan imagery

Panchromatic satellite image looks greyscale as it uses a single band for a greater spatial resolution. Pan-sharpening is a data fusion technique when the pan image is combined with a low-resolution multispectral image to achieve a higher resolution while preserving all spectral attributes.
The segmentation neural network is basically indifferent to pan-image if it's trained in an appropriate way of augmentation. E.g. the building footprints extraction model works good enough on panchromatic images as it used to be on RGB.