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.
At LRV 83 vs 24, White Dove is decisively the brighter choice.
Purbeck Stone reflects far more light (LRV 52 vs 24), opening up a space where Rock Gray encloses it.
Evergreen Fog reads slightly lighter (LRV 30 vs 24), a gap that shows most in low-lit rooms.
Agreeable Gray reflects far more light (LRV 60 vs 24), opening up a space where Rock Gray encloses it.
At LRV 58 vs 24, Accessible Beige is decisively the brighter choice.
A 3-point LRV gap (27 vs 24) makes Denim Drift the marginally brighter of the two.
French Gray reflects far more light (LRV 43 vs 24), opening up a space where Rock Gray encloses it.
At LRV 55 vs 24, Tranquil Dawn is decisively the brighter choice.
At LRV 44 vs 24, Hardwick White is decisively the brighter choice.
Pure White reflects far more light (LRV 84 vs 24), opening up a space where Rock Gray encloses it.
At LRV 66 vs 24, Balboa Mist is decisively the brighter choice.
At LRV 74 vs 24, Shoji White is decisively the brighter choice.
A 12-point LRV gap (24 vs 12) makes Rock Gray the marginally brighter of the two.
At LRV 24 vs 8, Rock Gray is decisively the brighter choice.
At LRV 68 vs 24, Skimming Stone is decisively the brighter choice.
A 12-point LRV gap (24 vs 12) makes Rock Gray the marginally brighter of the two.
At LRV 45 vs 24, Saybrook Sage is decisively the brighter choice.
Pale Green reads slightly lighter (LRV 31 vs 24), a gap that shows most in low-lit rooms.