Slate grey vs RAL 820-5
Slate grey (RAL Classic) and RAL 820-5 (RAL Effect) come from different manufacturers. Both sit in the blue-grey family, which is useful context if you're narrowing within a single hue direction. Their light reflectance values are nearly the same — 12 vs 9 — so neither will read significantly brighter or darker than the other. A ΔE of 1.5 puts them in subtle territory — distinguishable in direct comparison, less so from across a room. Below you'll find 2 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
Slate grey vs RAL 820-5 in Real Spaces
2 real rooms side by side. Slate grey and RAL 820-5 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
Bedrooms are typically lit with warmer, lower light than the rest of the house — a condition that flatters warm tones and deepens cool ones. In photos like these you're seeing the difference at its most direct. In a finished room, the distinction is there but not dramatic.
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. In photos like these you're seeing the difference at its most direct. In a finished room, the distinction is there but not dramatic.
Color Details
Slate grey vs RAL 820-5 Simulated Comparison
5 simulated room previews — drag the slider on each to see Slate grey on one side and RAL 820-5 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 Slate grey comparisons
See how Slate grey stacks up against other well-photographed colors across different brands and tones.
