RAL 660-1 vs Impromptu
RAL 660-1 (RAL Effect) and Impromptu (Sherwin-Williams) come from different manufacturers. These are both blues, so the question isn't which hue to choose — it's where within blue to land. The 8-point LRV gap — 23 for Impromptu vs 15 for RAL 660-1 — means Impromptu will open up a space more effectively. ΔE 6.4 means they're clearly different, but not dramatically so — they'd pair well in the same room. Below you'll find 5 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
RAL 660-1 vs Impromptu in Real Spaces
5 real rooms side by side. RAL 660-1 and Impromptu 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
A living room wall sees more varied light than almost any other surface in the house, which makes the choice between these two more nuanced than a chip suggests. Impromptu reads slightly lighter here — a subtle but real difference in how open the space feels.
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. Impromptu has the edge in reflectance, which shows as a quiet sense of added space rather than an obvious contrast.
Kitchen
Kitchens often have the harshest, most revealing light in the house — under-cabinet LEDs and overhead fixtures that strip away subtlety. Impromptu has the edge in reflectance, which shows as a quiet sense of added space rather than an obvious contrast.
Bathroom
Small bathrooms intensify color. A shade that seems quiet in a larger room can feel immersive when you're surrounded by it on four walls. Impromptu has the edge in reflectance, which shows as a quiet sense of added space rather than an obvious contrast.
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. Impromptu has the edge in reflectance, which shows as a quiet sense of added space rather than an obvious contrast.
Color Details
RAL 660-1 vs Impromptu Simulated Comparison
5 simulated room previews — drag the slider on each to see RAL 660-1 on one side and Impromptu 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 660-1 comparisons
See how RAL 660-1 stacks up against other well-photographed colors across different brands and tones.
White Dove reflects far more light (LRV 83 vs 15), opening up a space where RAL 660-1 encloses it.
At LRV 52 vs 15, Purbeck Stone is decisively the brighter choice.
At LRV 30 vs 15, Evergreen Fog is decisively the brighter choice.
At LRV 60 vs 15, Agreeable Gray is decisively the brighter choice.
Accessible Beige reflects far more light (LRV 58 vs 15), opening up a space where RAL 660-1 encloses it.
Denim Drift reflects far more light (LRV 27 vs 15), opening up a space where RAL 660-1 encloses it.
At LRV 43 vs 15, French Gray is decisively the brighter choice.
Tranquil Dawn reflects far more light (LRV 55 vs 15), opening up a space where RAL 660-1 encloses it.
Hardwick White reflects far more light (LRV 44 vs 15), opening up a space where RAL 660-1 encloses it.
At LRV 84 vs 15, Pure White is decisively the brighter choice.
Balboa Mist reflects far more light (LRV 66 vs 15), opening up a space where RAL 660-1 encloses it.
Shoji White reflects far more light (LRV 74 vs 15), opening up a space where RAL 660-1 encloses it.
RAL 660-1 reads slightly lighter (LRV 15 vs 12), a gap that shows most in low-lit rooms.
RAL 660-1 reads slightly lighter (LRV 15 vs 8), a gap that shows most in low-lit rooms.
Skimming Stone reflects far more light (LRV 68 vs 15), opening up a space where RAL 660-1 encloses it.
With LRVs of 15 and 12, the two reflect almost the same amount of light.
Saybrook Sage reflects far more light (LRV 45 vs 15), opening up a space where RAL 660-1 encloses it.
At LRV 31 vs 15, Pale Green is decisively the brighter choice.