RAL 850-4 vs Cornwall Slate
Where RAL 850-4 belongs to RAL Effect's range, Cornwall Slate is a Sherwin-Williams color. Both sit in the grey family, which is useful context if you're narrowing within a single hue direction. They have nearly identical light reflectance values (27 vs 29), so they'll read as similarly Medium in most lighting conditions. The ΔE 3.5 gap is real but not dramatic — close enough to use together, distinct enough to matter as a choice. Below you'll find 4 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
RAL 850-4 vs Cornwall Slate in Real Spaces
4 real rooms side by side. RAL 850-4 and Cornwall Slate 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.
Living Room
In a living room, color works across both daylight and evening light — the same wall can read very differently at noon and at 8pm. Side by side like this, the difference is easy to read — which is exactly why seeing them in a real space is more useful than comparing chips.
Bedroom
The context that matters most in a bedroom is how a color reads under a bedside lamp at night, not under noon daylight. The distinction reads clearly at room scale, making the choice between them concrete.
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. The distinction reads clearly at room scale, making the choice between them concrete.
Kitchen Cabinets
Kitchen cabinets are constantly compared against adjacent materials, which means subtle differences between these two become much more visible. The distinction reads clearly at room scale, making the choice between them concrete.
Color Details
RAL 850-4 vs Cornwall Slate Simulated Comparison
5 simulated room previews — drag the slider on each to see RAL 850-4 on one side and Cornwall Slate 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 RAL 850-4 comparisons
See how RAL 850-4 stacks up against other well-photographed colors across different brands and tones.
White Dove reflects far more light (LRV 83 vs 27), opening up a space where RAL 850-4 encloses it.
At LRV 52 vs 27, Purbeck Stone is decisively the brighter choice.
A 3-point LRV gap (30 vs 27) makes Evergreen Fog the marginally brighter of the two.
At LRV 60 vs 27, Agreeable Gray is decisively the brighter choice.
Accessible Beige reflects far more light (LRV 58 vs 27), opening up a space where RAL 850-4 encloses it.
With LRVs of 27 and 27, the two reflect almost the same amount of light.
At LRV 43 vs 27, French Gray is decisively the brighter choice.
Tranquil Dawn reflects far more light (LRV 55 vs 27), opening up a space where RAL 850-4 encloses it.
Hardwick White reflects far more light (LRV 44 vs 27), opening up a space where RAL 850-4 encloses it.
At LRV 84 vs 27, Pure White is decisively the brighter choice.
Balboa Mist reflects far more light (LRV 66 vs 27), opening up a space where RAL 850-4 encloses it.
Shoji White reflects far more light (LRV 74 vs 27), opening up a space where RAL 850-4 encloses it.
RAL 850-4 reflects far more light (LRV 27 vs 12), opening up a space where Pewter Green encloses it.
Skimming Stone reflects far more light (LRV 68 vs 27), opening up a space where RAL 850-4 encloses it.
RAL 850-4 reflects far more light (LRV 27 vs 12), opening up a space where Vintage Vogue encloses it.
Saybrook Sage reflects far more light (LRV 45 vs 27), opening up a space where RAL 850-4 encloses it.
A 4-point LRV gap (31 vs 27) makes Pale Green the marginally brighter of the two.
At LRV 27 vs 7, RAL 850-4 is decisively the brighter choice.
Their light reflectance is nearly identical (LRV 27 vs 24), so neither reads brighter in a room.
At LRV 57 vs 27, Guilford Green is decisively the brighter choice.