They call it Mellow vs Thunder Gray
Both from Sherwin-Williams's palette. They call it Mellow reads as beige, while Thunder Gray reads as grey — two distinct hue families, not close cousins. They call it Mellow (LRV 79) reflects noticeably more light than Thunder Gray (LRV 9), a difference of 70 points that becomes especially apparent in rooms with limited natural light. They call it Mellow runs warm while Thunder Gray is decidedly neutral, which means they'll respond very differently to warm vs cool light sources. With a ΔE of 60.1, the contrast is hard to miss. These aren't variations on a theme — they're two different answers to the same question. Below you'll find 2 real-room photo comparisons where both colors appear side by side, plus 5 simulated room previews.
They call it Mellow vs Thunder Gray in Real Spaces
2 real rooms side by side. Seeing They call it Mellow and Thunder Gray in actual rooms makes the difference concrete; browse the spaces below to get a feel for how each color lives on a wall.
Kitchen
In a kitchen, colors are seen under bright task lighting that amplifies undertones — what reads neutral elsewhere can show its hand here. They call it Mellow reflects noticeably more light off the walls, making the space read more open than Thunder Gray.
House
Seen across an entire facade, subtle tonal differences become pronounced. What reads as nearly the same on a chip often reads as clearly different at scale. They call it Mellow reflects noticeably more light off the walls, making the space read more open than Thunder Gray.
Color Details
They call it Mellow vs Thunder Gray Simulated Comparison
5 simulated room previews — drag the slider on each to see They call it Mellow on one side and Thunder Gray 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.