Warm Onyx vs Black grey
Warm Onyx (Behr) and Black grey (RAL Classic) come from different manufacturers. Hue-wise, Warm Onyx belongs to the grey family and Black grey to the blue-grey family. Their light reflectance values are nearly the same — 7 vs 6 — so neither will read significantly brighter or darker than the other. A ΔE of 11.3 puts these firmly in different territory — two distinct design choices rather than close alternatives. Below you'll find 2 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
Warm Onyx vs Black grey in Real Spaces
2 real rooms side by side. Seeing Warm Onyx and Black grey in actual rooms makes the difference concrete; browse the spaces below to get a feel for how each color lives on a wall.
Living Room
A living room wall sees more varied light than almost any other surface in the house, which makes the choice between these two more nuanced than a chip suggests. The distinction reads clearly at room scale, making the choice between them concrete.
House
A full exterior is the most demanding test for a paint color — scale and outdoor light both amplify differences that seem small on a swatch. At this scale, the choice between them becomes clear in a way that a swatch alone can't communicate.
Color Details
Warm Onyx vs Black grey Simulated Comparison
5 simulated room previews — drag the slider on each to see Warm Onyx on one side and Black grey on the other.
Digital color is approximate. These simulations are generated from the manufacturer's hex values and overlaid on grayscale room photos — your screen's calibration, brightness, and viewing angle all affect how they render. Before committing to either color, test physical samples in your own space under the light you actually live with.
More Warm Onyx comparisons
See how Warm Onyx stacks up against other well-photographed colors across different brands and tones.
