I'm looking into who did the coloring for some other comics, so I also wondered about Moomin. There's colored versions of the comics, but this review says they detract from the experience:
https://theslingsandarrows.com/moomin-falls-in-love/
Unfortunately the colouring is frequently at odds with Jansson’s art, introducing many graphic shapes and background additions which disrupt her original layouts, and is intrusive enough to prevent a five star rating.
I see what they're getting at, the sleeve of La Goona's dress doesn't lend itself well to color, they just kind of faded it in there. The horse also would probably be colored completely differently instead of a black base if it was natively colored. Moomin's blush in that comic probably wouldn't be black.
Peanuts is drawn in a style that lends itself better overall to coloring, but sometimes has issues, like the water in the pool in this comic:
https://discuss.online/post/43310351
The original is mostly black, and the coloring can only add a bit of blue on top. Schroeder's swim trunks probably also wouldn't have been black if originally drawn in color.