Colour holds are the unsung architecture of a superhero cover. A hard hold around a cape can save a busy city. A lazy hold lets the skyline crawl onto a shoulder and stay there.
On Marvel NFT files, holds sometimes arrive as a single saturated field with no temperature shift. Print colourists used to sneak a cooler edge against brick. Digital wraps, chasing punch in a small icon, often skip that edge.
Night covers are the usual failure. Blue rain, blue steel, blue costume: the figure becomes weather. A review that only says “moody” has not done the work.
If you commission a splash-page critique, expect a paragraph on holds. It is the fastest way to explain why a wrap looks loud in a grid and tired at full size.