How this match is calculated
Every RAL and Sherwin-Williams 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.
Obstinate Orange ranks as the closest Sherwin-Williams equivalent to Pure Orange because it sits nearest in that perceptual space. There is a visible difference between them, so treat this as the closest available option rather than an exact dupe. Sheen, lighting, and the existing wall color all shift perceived color, so order a sample of Obstinate Orange and check it in your actual room before committing.