How this match is calculated
Every Sherwin-Williams and Dutch Boy color in our database is converted to CIELAB coordinates, then scored with the CIEDE2000 formula — the current ISO standard for how different two colors look to the human eye. It corrects for the fact that the eye notices small shifts in some hue ranges far more than others, so it predicts real-world appearance more reliably than comparing hex codes directly.
Purple Tulips ranks as the closest Dutch Boy equivalent to Passionate Purple because it sits nearest in that perceptual space. The two are near-identical — most people won't read them as different colors once they're on a wall. Sheen, lighting, and the existing wall color all shift perceived color, so order a sample of Purple Tulips and check it in your actual room before committing.