Black Blue

Technical Profile

What color is Black Blue? It's a dark cool gray with the hex code #18171C. Black Blue is a distinctive shade in the RAL lineup, and while close cross-brand equivalents exist, its specific blend of cool tone and dark depth gives it a character worth comparing in person. Black Blue has a neutral undertone, which affects how it pairs with trim, flooring, and adjacent wall colors. Understanding a color's undertone is key to avoiding combinations that clash — it often matters more than the surface color itself. Black Blue (#18171C) by RAL is a dark gray paint color with a understated, nearly neutral quality. It delivers a bold depth that creates intimate, cocooning spaces. On the temperature spectrum this shade carries a cool cast, lending calm and collected elegance. Its RGB channels are closely balanced, contributing to its neutral, even-keeled visual character. With an LRV of only 9, this color absorbs nearly all light, producing a dramatic, cocoon-like effect. A dark neutral this deep brings modern drama to feature walls, built-in cabinetry, and exterior accents while remaining easier to coordinate than a saturated color. For dark shades, a satin finish helps the color look its best by adding a gentle luminosity, while flat finishes create a more velvety, matte effect. For color coordination, Black Blue pairs beautifully with green tones for bold complementary contrast, or with neighboring purple and blue hues for a harmonious, flowing palette. Its neutral undertone means trim and ceiling whites should lean neutral to avoid a jarring clash. If RAL is unavailable in your area, close cross-brand alternatives exist from MPC. In terms of mood and atmosphere, Black Blue creates a brooding, midnight atmosphere that feels both dramatic and deeply restful. Designers often reach for shades like this when the goal is to shape how a room feels, not just how it looks. This shade is a natural fit for a wide range of interior design styles. As part of the RAL palette, Black Blue benefits from a curated selection of coordinating colors that the brand recommends for trim, accent, and ceiling pairings. Because Black Blue has a low LRV, it can look dramatically different under incandescent versus daylight bulbs — always test a large swatch on the actual wall before committing. Deep shades generally benefit from a quality primer and may require an extra coat for even, streak-free coverage. Dark paint colors benefit from rich material pairings: think thick wool throws, aged leather, matte black hardware, and warm metallic accents in copper or brass. You can order Black Blue (5004) directly from RAL or through major paint retailers, and we recommend purchasing a peel-and-stick sample to preview it on your wall before buying gallons.