Hey there! Unlike DriveThruRPG, creators on DM's Guild are limited on whether they can offer POD. You have to have at least a Gold bestselling title to submit your title for POD. Once you've met that requirement, you can publish hardcover or softcover or both as well as paper type variations (premium color vs. standard color).
In our experience, there isn't a detectable difference between the premium and standard color. (Our research also shows that the difference between them would be more noticeable when publishing a coffee table book of photos or something along those lines.) Premium color is also much more expensive, which means the customer price would have to go up. Since there isn't a noticeable difference with premium and it would cause the customer cost to raise, we plan to only offer standard color.
As for hardcover or softcover, we have historically offered one or both options. For this one, we're only planning hardcover at this time, mostly due to its size (180 pages). If there's enough interest in softcover though, we might add that later on.