Neptune Blue

Technical Profile

What color is Neptune Blue? It's a medium cool blue with the hex code #39729C. Colors similar to Neptune Blue include Benjamin Moore Winter's, Benjamin Moore Chicago Blues, Kilz Triumph Blue. Comparing swatches side by side is the best way to spot the subtle differences that distinguish these close color relatives. Neptune Blue has a cool (blue) 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. Neptune Blue (#39729C) by Behr is a medium blue paint color with a balanced saturation that feels natural and approachable. It delivers a versatile mid-tone depth that anchors a room without overwhelming it. On the temperature spectrum this shade carries a cool cast, lending calm and collected elegance. In its RGB breakdown, blue is the dominant channel, which gives it a subtle cool, atmospheric depth even under different lighting conditions. A Light Reflectance Value of 41 gives it moderate light reflection, striking a balance between brightness and depth. This mid-tone blue brings confidence and calm to home offices, accent walls, and kitchen islands. A satin or eggshell finish brings out the richness at this depth, and the slight sheen makes walls easier to maintain. For color coordination, Neptune Blue pairs beautifully with orange tones for bold complementary contrast, or with neighboring blue and teal hues for a harmonious, flowing palette. Its cool (blue) undertone means trim and ceiling whites should lean neutral to avoid a jarring clash. If Behr is unavailable in your area, close cross-brand alternatives exist from Benjamin Moore, Kilz, MPC and others. In terms of mood and atmosphere, Neptune Blue delivers a composed, professional calm often favored in contemporary and Scandinavian-inspired interiors. 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 nautical, classic traditional, and Hamptons-style interiors. As part of the Behr palette, Neptune Blue benefits from a curated selection of coordinating colors that the brand recommends for trim, accent, and ceiling pairings. As with any paint color, Neptune Blue can shift noticeably between natural daylight, warm incandescent, and cool LED lighting — testing a sample swatch on your wall under different conditions is always recommended. Mid-tone shades like this look best when balanced with a mix of textures — think leather seating, brushed brass hardware, woven wool, and raw-edge wood. You can order Neptune Blue (570D-6) directly from Behr or through major paint retailers, and we recommend purchasing a peel-and-stick sample to preview it on your wall before buying gallons.