How this match is calculated
Every Sherwin-Williams and Vista Paint 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.
The Open Range ranks as the closest Vista Paint equivalent to Fusion 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 The Open Range and check it in your actual room before committing.