This is essentially the UW Madison GI Segmentation Contest's data which has been pre-processed for easier use for later projects and easier processing. The colours of the segmentations are:

COLORS = {"large_bowel": (1, 0, 0), "small_bowel": (0, 1, 0), "stomach": (0, 0, 1)} 

Feel free to use this and also do upvote it!