Pure White vs Extra White
Two cool, minimal-undertone Sherwin-Williams whites two points of LRV apart (84 vs 86). Extra White is the brighter, slightly cooler of the two; Pure White carries a touch more warmth and is the more common whole-house choice.
Pick Pure White for walls or a whole-house color where you want a clean white without any warm cream cast, but not the starkest option on the fan deck.
Pick Extra White for trim, exterior siding, or a kitchen that wants the brightest, coolest white available, especially against black or dark accents.
How close are they?
Delta-E (perceptual color distance) between Pure White and Extra White is 3.3 (a visible but subtle difference, more apparent side by side than in separate rooms). LRV runs 84 for Pure White versus 86 for Extra White, a 2-point gap.