Are you a coward? Are you a ray of sunshine? Is ‘Yellow’ just the name of a song?

Yellow: /ˈjɛləʊ/ A colour, an adjective that can have completely different meanings depending on context.

I love the use of ‘yellowing’ in the second stanza of Carol Ann Duffy’s Havisham.

…Whole days
in bed cawing Nooooo at the wall; the dress
yellowing, trembling if I open the wardrobe;”

How would you describe something as yellow?