Rock Gray vs RAL 820-4
Where Rock Gray belongs to Benjamin Moore's range, RAL 820-4 is a RAL Effect color. Rock Gray reads as grey, while RAL 820-4 reads as blue-grey — two distinct hue families, not close cousins. They have nearly identical light reflectance values (24 vs 23), so they'll read as similarly Dark in most lighting conditions. At ΔE 1.7, these are close — the kind of difference that matters when choosing between them, but doesn't read strongly in a finished room. Below you'll find 3 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
Rock Gray vs RAL 820-4 in Real Spaces
3 real rooms side by side. Rock Gray and RAL 820-4 are close enough that the difference can be hard to judge from a chip alone — these photos show how each reads at scale, across different spaces and lighting conditions.
Bedroom
The context that matters most in a bedroom is how a color reads under a bedside lamp at night, not under noon daylight. At this scale the difference is subtle — you'd need them side by side, as shown here, to reliably tell them apart.
Bathroom
Bathrooms are one of the few spaces where you're genuinely enclosed by the paint color, which makes the choice between these two more consequential. At this scale the difference is subtle — you'd need them side by side, as shown here, to reliably tell them apart.
Kitchen Cabinets
Kitchen cabinets are constantly compared against adjacent materials, which means subtle differences between these two become much more visible. At this scale the difference is subtle — you'd need them side by side, as shown here, to reliably tell them apart.
Color Details
Rock Gray vs RAL 820-4 Simulated Comparison
5 simulated room previews — drag the slider on each to see Rock Gray on one side and RAL 820-4 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 Rock Gray comparisons
See how Rock Gray stacks up against other well-photographed colors across different brands and tones.
