Final answer:
The narrator describes the color of the wallpaper as a 'repellent,' 'unclean yellow,' and compares the smell to a 'yellow smell,' illustrating the vivid and unpleasant sensory experience it creates.
Step-by-step explanation:
The narrator describes the color of the wallpaper in various passages throughout the text, using descriptive and figurative language to convey its disturbing nature. She notes the color as a "repellent", "unclean yellow", and emphasizes how it is "strangely faded by the slow-turning sunlight." But most notably, she personifies the smell of the wallpaper by saying, "But now I am used to it. The only thing I can think of that it is like is the color of the paper! A yellow smell." This description vividly illustrates the overarching presence and the unpleasantness of the wallpaper's color and smell combined.