It’s small and yellow mostly, with a picture of a man kind of faces to the side but not his full profile (he was black with short hair, and a suit?). The title of the book was purple and the only word in the title I remember is “King”.

[Kris]

Adda, is this book for kids, teens or adults?

What's the tone - e.g., funny, serious, angsty, romantic, etc.?

[Rainbowheart]

The Kingdom on the Waves?

[Adele]

This is kind of a stretch but .. The Fisher King: A Novel

[Adele]

Another guess: King Comus

[Kris]

OP (original poster) account is deleted. Moving to the "Now we'll never know" folder.