Note that the Baldwin is a 15x18 locomotive (D&RG class 56) while the Grant is a 15x20 locomotive (D&RG class 60). The biggest visual difference was the height of the tender, although that's not absolute since a few early Baldwin-built class 60 engines (like the one that became Silverton RR #100) had the smaller tenders. I like the Baldwin stack and domes a little better.
Too bad all they had back then was black & white photography. The paint styles were quite pretty and the loss of information with B&W is unfortunate. The Baldwin pictured was primarily olive green as a base color. I don't know for certain what color Grant painted its engines, but the Baldwin 15x20 engines built at the same time were painted black base color, as were the other Baldwin D&RG locomotives being built by 1881-1882. Trim would've been yellow, white, and red. The line trim and lettering appears broadly similar between the two, the Baldwin being perhaps a little more elaborate (or possibly not--the Grant image isn't as clear) but both within the norm for the time.