Final answer:
The wallpaper in the narrator's room/nursery is described as dull yet lurid orange in some places, a sickly sulphur tint in others. The narrator finds it awful and horrid.
Step-by-step explanation:
The best description of the wallpaper in the narrator's room/nursery is dull yet lurid orange in some places, a sickly sulphur tint in others.
The narrator expresses their dislike for the wallpaper, describing it as awful and horrid. The color and pattern of the wallpaper contribute to the overall negative impression of the room.