Cobalt Blue Color Palette
Cobalt Blue is hex #0047AB, rgb(0, 71, 171). Cobalt blue is a deep, intense blue originally made from cobalt salts. It is more saturated than navy and feels vivid, dependable and modern.
By Mohamed Farhan · Updated Oct 19, 2026
Cobalt Blue color codes
Reading the cobalt blue color codes
The hex code #0047AB is three pairs of base-16 numbers for red, green and blue. 00 is 0, 47 is 71 and AB is 171, each on a scale from 0 to 255. That is why the same color is written rgb(0, 71, 171) in CSS. The blue channel is the strongest here, which is what gives cobalt blue its blue character.
HSL describes the same color the way people think about it. A hue of 215 degrees places cobalt blue in the blue part of the color wheel. Saturation of 100% makes it vivid, and lightness of 34% makes it a dark color. HSL is the easiest format to adjust by hand: keep the hue, then raise or lower lightness to create tints and shades that stay in the same family.
For print, the approximate CMYK mix is 100% cyan, 58% magenta, 0% yellow and 33% black. Screen and print colors never match perfectly, because monitors emit light while ink absorbs it, so always proof a printed sample before committing to cobalt blue for packaging or stationery. See MDN's guide to CSS color values for every format browsers accept.
Cobalt Blue shades and tints
A full 50 to 950 scale built around #0047AB, so you can use cobalt blue for backgrounds, borders, buttons and text without leaving the family. Click any shade to copy it.
// tailwind.config.js
theme: {
extend: {
colors: {
"cobalt-blue": {
50: "#D6E2F2",
100: "#B8CBE7",
200: "#99B5DD",
300: "#7A9FD3",
400: "#5C89C9",
500: "#3D73BF",
600: "#1F5DB5",
700: "#0047AB",
800: "#003A8B",
900: "#002C6B",
950: "#001F4A",
},
},
},
}:root {
--cobalt-blue-50: #D6E2F2;
--cobalt-blue-100: #B8CBE7;
--cobalt-blue-200: #99B5DD;
--cobalt-blue-300: #7A9FD3;
--cobalt-blue-400: #5C89C9;
--cobalt-blue-500: #3D73BF;
--cobalt-blue-600: #1F5DB5;
--cobalt-blue-700: #0047AB;
--cobalt-blue-800: #003A8B;
--cobalt-blue-900: #002C6B;
--cobalt-blue-950: #001F4A;
}A shade-by-shade guide to cobalt blue
The 50 to 950 scale above follows the same structure as Tailwind's built-in palettes, so each step has a natural job. The lightest steps, 50 (#D6E2F2) and 100 (#B8CBE7), are page and card backgrounds: they carry the cobalt blue mood without competing with content. Steps 200 (#99B5DD) and 300 (#7A9FD3) suit borders, dividers, hover states and selected rows.
The middle of the scale, 400 to 600, is where cobalt blue is most recognizable, so use it for brand moments, illustrations and primary buttons. White text reaches the 4.5:1 body-text contrast minimum from step 500 upward, so use step 500 or darker when a button label needs to be white. Near-black text stays readable on steps 50 to 400.
The darkest steps, 800 (#003A8B) through 950 (#001F4A), make headings, body text and dark-mode surfaces that stay clearly related to cobalt blue. Using step 900 or 950 for text instead of pure black is one of the simplest ways to make an interface feel designed rather than default.
Colors that go with cobalt blue
How the cobalt blue color combinations work
Complementary. Directly across the color wheel from cobalt blue is #AB6400, which sits closest to burnt orange among common named colors. Complementary pairs create the strongest contrast of hue, so use the second color sparingly, for a single call to action or highlight, rather than in equal amounts.
Analogous. #009DAB and #0E00AB sit 30 degrees either side of cobalt blue. Analogous palettes feel calm and cohesive because the colors share undertones; they are ideal for illustrations, gradients and backgrounds where you want harmony more than contrast.
Triadic and split complementary. The triadic set (#AB0047 and #47AB00) is evenly spaced around the wheel and feels playful; the second color is closest to crimson. The split complementary set (#AB0E00 and #9DAB00) keeps much of the complementary contrast but is easier to balance, which makes it a good choice for data visualization and multi-category tags.
Monochromatic. The monochromatic set runs from #4592FF to #001129. A single-hue palette is the safest way to build a calm, premium interface: rely on lightness for hierarchy, then add one neutral and one accent if you need emphasis.
Cobalt Blue compared with similar colors
denim blue (#1560BD) is lighter (41% vs 34% lightness) and more muted, and shares almost the same hue. Choose denim blue if you want a softer, airier version; choose cobalt blue if you want its specific balance of brightness and color.
cerulean (#007BA7) is about as light and similarly saturated, and leans back the wheel toward cyan. Choose cerulean if you need more weight and contrast; choose cobalt blue if you want its specific balance of brightness and color.
skobeloff (#007474) is darker (23% vs 34% lightness) and similarly saturated, and leans back the wheel toward cyan. Choose skobeloff if you need more weight and contrast; choose cobalt blue if you want its specific balance of brightness and color.
Cobalt Blue in a real interface
Swatches only tell half the story. Here cobalt blue carries the primary action, with tints from its own scale for the surface and panels.
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Using cobalt blue in UI: buttons, text, backgrounds and dark mode
- Buttons. Cobalt Blue carries white labels at 8.44:1, which passes AA for normal text.
- Text. Cobalt Blue works as text on white backgrounds.
- Backgrounds. Use steps 50 and 100 for large areas and keep the base color for smaller surfaces. Big blocks of a vivid dark color draw attention, so give them a reason, like a hero section or pricing highlight.
- Dark mode. Steps 900 and 950 make a dark surface tinted with cobalt blue. On dark backgrounds the base color often needs a lighter step (300 or 400) to keep enough contrast for icons and borders, as required by WCAG non-text contrast.
- States. Shift one step darker for hover and two steps darker for pressed. Keep focus rings in a contrasting color so keyboard users can always see them.
Contrast and accessibility
AA needs 4.5:1 for body text and 3:1 for large text. AAA needs 7:1.
Color contrast is measured as a ratio from 1:1 (no contrast) to 21:1 (black on white). Cobalt Blue scores 8.44:1 against white (AAA) and 2.49:1 against black (Fail). The WCAG 2.1 contrast guideline asks for at least 4.5:1 for normal text and 3:1 for large text, which is why the shade guide above recommends specific steps for text and labels.
Contrast is only half of accessibility. Around 1 in 12 men and 1 in 200 women have some form of color vision deficiency, so never use cobalt blue alone to signal meaning such as success, error or selection. Pair it with an icon, a label or a change in weight.
What cobalt blue means
Blue is the most trusted color in digital products. It signals stability, competence and calm, which is why banks, SaaS tools and health platforms default to it.
Cobalt blue is a pigment made from cobalt oxide and alumina, developed in its modern form by Louis Jacques Thénard in 1802. It has been prized in ceramics and painting for its intensity.
Because so many products already use blue, the shade matters more than the hue. Pair it with an unexpected neutral or accent so the interface does not look like every other dashboard.
Where cobalt blue works best
- Tech and SaaS
- Ceramics and art
- Fintech
- Sports teams
How to style cobalt blue
Cobalt pairs with white, amber, coral and charcoal. It supports white text, making it a strong primary color for buttons and links in SaaS and fintech.
Build a UI with cobalt blue
Inspo AI generates a full React + Tailwind screen using #0047AB as the brand color, grounded in real shipped designs.
Sources and further reading
- Wikipedia: Cobalt Blue · History and definition of cobalt blue.
- WCAG 2.1: Contrast (Minimum) · The W3C rule behind the 4.5:1 and 3:1 thresholds used on this page.
- WCAG 2.1: Use of Color · Why color should never be the only way information is shown.
- MDN: CSS color values · Reference for hex, rgb() and hsl() syntax.
- Tailwind CSS: Customizing colors · How to add a custom color scale to your theme.
Similar colors
Questions people ask
What is the hex code for cobalt blue?
The hex code for cobalt blue used on this page is #0047AB. In RGB that is rgb(0, 71, 171), and in HSL it is hsl(215, 100%, 34%).
What colors go well with cobalt blue?
Cobalt Blue pairs well with #002B66, #EAF1FB, #F4B942 (the Kiln Glaze palette above). Its complementary color is #AB6400, and analogous colors are #009DAB and #0E00AB.
Is cobalt blue a warm or cool color?
Cobalt Blue is a cool color. Its hue sits at 215 degrees on the color wheel with 100% saturation.
Can I use cobalt blue for text?
Cobalt Blue has a contrast ratio of 8.44:1 against white and 2.49:1 against black. Body text needs at least 4.5:1, so it works as text on white backgrounds.
What does cobalt blue mean?
Blue is the most trusted color in digital products. It signals stability, competence and calm, which is why banks, SaaS tools and health platforms default to it. Cobalt Blue in particular is used for tech and saas and ceramics and art.
How do I use cobalt blue in Tailwind CSS?
Use an arbitrary value like bg-[#0047AB] for a one-off, or add the 50-950 scale from this page to theme.extend.colors in tailwind.config.js and use classes like bg-cobalt-blue-500 and text-cobalt-blue-900.
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