Slippery Shale vs RAL 840-4
Slippery Shale (Behr) and RAL 840-4 (RAL Effect) come from different manufacturers. These are both greys, so the question isn't which hue to choose — it's where within grey to land. The 3-point LRV gap — 21 for RAL 840-4 vs 18 for Slippery Shale — means RAL 840-4 will open up a space more effectively. ΔE 4.2 means they're clearly different, but not dramatically so — they'd pair well in the same room. Below you'll find 2 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
Slippery Shale vs RAL 840-4 in Real Spaces
2 real rooms side by side. Slippery Shale and RAL 840-4 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.
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.
Kitchen Cabinets
Cabinet color is always seen in context — against countertops, backsplash, and hardware — which amplifies undertone differences that might disappear on a plain wall. At this scale, the choice between them becomes clear in a way that a swatch alone can't communicate.
Color Details
Slippery Shale vs RAL 840-4 Simulated Comparison
5 simulated room previews — drag the slider on each to see Slippery Shale on one side and RAL 840-4 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 Slippery Shale comparisons
See how Slippery Shale stacks up against other well-photographed colors across different brands and tones.
White Dove reflects far more light (LRV 83 vs 18), opening up a space where Slippery Shale encloses it.
At LRV 69 vs 18, Ammonite is decisively the brighter choice.
Slippery Shale reflects far more light (LRV 18 vs 6), opening up a space where Iron Ore encloses it.
At LRV 52 vs 18, Purbeck Stone is decisively the brighter choice.
At LRV 30 vs 18, Evergreen Fog is decisively the brighter choice.
Mizzle reflects far more light (LRV 52 vs 18), opening up a space where Slippery Shale encloses it.
At LRV 60 vs 18, Agreeable Gray is decisively the brighter choice.
Accessible Beige reflects far more light (LRV 58 vs 18), opening up a space where Slippery Shale encloses it.
Denim Drift reads slightly lighter (LRV 27 vs 18), a gap that shows most in low-lit rooms.
At LRV 43 vs 18, French Gray is decisively the brighter choice.
At LRV 18 vs 4, Slippery Shale is decisively the brighter choice.
Tranquil Dawn reflects far more light (LRV 55 vs 18), opening up a space where Slippery Shale encloses it.
Slippery Shale reads slightly lighter (LRV 18 vs 13), a gap that shows most in low-lit rooms.
Hardwick White reflects far more light (LRV 44 vs 18), opening up a space where Slippery Shale encloses it.
At LRV 84 vs 18, Pure White is decisively the brighter choice.
A 3-point LRV gap (21 vs 18) makes Artichoke the marginally brighter of the two.
Balboa Mist reflects far more light (LRV 66 vs 18), opening up a space where Slippery Shale encloses it.
Shoji White reflects far more light (LRV 74 vs 18), opening up a space where Slippery Shale encloses it.
Snowbound reflects far more light (LRV 83 vs 18), opening up a space where Slippery Shale encloses it.
Slippery Shale reads slightly lighter (LRV 18 vs 12), a gap that shows most in low-lit rooms.
Skimming Stone reflects far more light (LRV 68 vs 18), opening up a space where Slippery Shale encloses it.
At LRV 41 vs 18, Dix Blue is decisively the brighter choice.
At LRV 68 vs 18, Calamine is decisively the brighter choice.
A 6-point LRV gap (25 vs 18) makes Treron the marginally brighter of the two.
Slippery Shale reads slightly lighter (LRV 18 vs 12), a gap that shows most in low-lit rooms.
Saybrook Sage reflects far more light (LRV 45 vs 18), opening up a space where Slippery Shale encloses it.
At LRV 31 vs 18, Pale Green is decisively the brighter choice.
A 11-point LRV gap (18 vs 7) makes Slippery Shale the marginally brighter of the two.
A 6-point LRV gap (24 vs 18) makes Cement grey the marginally brighter of the two.
At LRV 57 vs 18, Guilford Green is decisively the brighter choice.