#02437f
a dark, electric blue · cool · closest name: Dark Slate Blue
Token name suggestion: Slate Sapphire
#02437f is a dark electric blue, 209° on the wheel and 99/100 on the cool side. Put white text on it (9.94:1). As text it scores 9.94:1 on white — safe at any size. Nearest name is Dark Slate Blue, nearest Tailwind family is slate.
At a glance
Every number on this page in one read: what #02437f is made of, how bright it looks, and which way it leans.
Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #02437f.
Reads cool. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.
Green carries most of what the eye calls brightness — that is why WCAG weights it 0.7152.
Every format
| HEX | #02437f |
| HEX (8-digit) | #02437fff |
| RGB | rgb(2, 67, 127) |
| RGBA | rgba(2, 67, 127, 1) |
| HSL | hsl(209, 97%, 25%) |
| HSV / HSB | hsv(209, 98%, 50%) |
| HWB | hwb(209 1% 50%) |
| CMYK | cmyk(98%, 47%, 0%, 50%) |
| LAB | lab(28.3 6.7 -38.9) |
| LCH | lch(28.3 39.5 279.8) |
| OKLCH | oklch(0.383 0.117 253.1) |
| XYZ (D65) | xyz(5.86, 5.56, 20.84) |
| Decimal | 148351 |
| Display P3 | color(display-p3 0.008 0.263 0.498) |
| Web-safe | #003366 |
Copy-ready code
/* CSS */
color: #02437f;
background-color: #02437f;
/* CSS custom property */
--brand: #02437f;
/* Tailwind (arbitrary) */
class="text-[#02437f] bg-[#02437f]"
/* SCSS */
$brand: #02437f;
/* SwiftUI */
Color(red: 0.008, green: 0.263, blue: 0.498)
/* UIKit */
UIColor(red: 0.008, green: 0.263, blue: 0.498, alpha: 1)
/* Android XML */
<color name="brand">#02437F</color>
/* Android Compose */
Color(0xFF02437F)
/* Flutter */
Color(0xFF02437F)
/* Python / OpenCV (BGR) */
(127, 67, 2)
/* Python / PIL (RGB) */
(2, 67, 127)
/* Java AWT */
new Color(2, 67, 127)
/* .NET */
Color.FromArgb(255, 2, 67, 127)
/* OpenGL / Unity (0–1) */
(0.0078f, 0.2627f, 0.4980f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{2,67,127}/* mix without leaving CSS */ background: color-mix(in oklab, #02437f 85%, white); border-color: color-mix(in oklab, #02437f 40%, transparent); /* theme-aware in one line */ color: light-dark(#02427E, #D3E1EE); /* relative colour syntax */ --hover: hsl(from #02437f h s calc(l - 7));
Design tokens
The same ramp in the four formats a team actually needs. Paste one and the whole palette lands with it.
:root {
--brand-50: #F1F8FD;
--brand-100: #E4F0FC;
--brand-200: #C1DFFB;
--brand-300: #91C9FD;
--brand-400: #59AEFC;
--brand-500: #2293FC;
--brand-600: #047FF1;
--brand-700: #036AC9;
--brand-800: #0355A1;
--brand-900: #02437f;
--brand-950: #042848;
--brand: #02437f;
--brand-ink: #ffffff;
--brand-surface: #F4F7FA;
--brand-border: #C0D7ED;
--brand-hover: #01305C;
--brand-pressed: #011E39;
}
@media (prefers-color-scheme: dark) {
:root {
--brand-surface: #141C24;
--brand-ink: #D3E1EE;
}
}theme: {
extend: {
colors: {
brand: {
50: '#F1F8FD',
100: '#E4F0FC',
200: '#C1DFFB',
300: '#91C9FD',
400: '#59AEFC',
500: '#2293FC',
600: '#047FF1',
700: '#036AC9',
800: '#0355A1',
900: '#02437f',
950: '#042848',
DEFAULT: '#02437f',
},
},
},
}$brand: (
'50': #F1F8FD,
'100': #E4F0FC,
'200': #C1DFFB,
'300': #91C9FD,
'400': #59AEFC,
'500': #2293FC,
'600': #047FF1,
'700': #036AC9,
'800': #0355A1,
'900': #02437f,
'950': #042848,
);
$brand-base: #02437f;
$brand-ink: #ffffff;
@function brand($step) { @return map-get($brand, $step); }{
"color": {
"brand": {
"50": { "$value": "#F1F8FD", "$type": "color" },
"100": { "$value": "#E4F0FC", "$type": "color" },
"200": { "$value": "#C1DFFB", "$type": "color" },
"300": { "$value": "#91C9FD", "$type": "color" },
"400": { "$value": "#59AEFC", "$type": "color" },
"500": { "$value": "#2293FC", "$type": "color" },
"600": { "$value": "#047FF1", "$type": "color" },
"700": { "$value": "#036AC9", "$type": "color" },
"800": { "$value": "#0355A1", "$type": "color" },
"900": { "$value": "#02437f", "$type": "color" },
"950": { "$value": "#042848", "$type": "color" }
},
"brandInk": { "$value": "#ffffff", "$type": "color" }
}
}Best text color
Only one of black and white can be right. This is the one, with the number that proves it.
Make it accessible
A contrast checker tells you that you failed. This tells you what to ship instead — same hue, same saturation, lightness moved only as far as WCAG demands.
Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #02437F is enough for headings on white. Non-text elements such as icons, chart strokes and focus rings also sit at 3:1 under WCAG 2.2 (1.4.11).
Accessibility — WCAG contrast
Contrast is symmetric, so each row covers both directions: #02437f as text on that neutral, and that neutral as text on #02437f.
| Neutral | Ratio | Verdict | Both directions |
|---|---|---|---|
| White#ffffff | 9.94:1 | AAAA lgAAA | AaAa |
| Slate 50#f8fafc | 9.50:1 | AAAA lgAAA | AaAa |
| Slate 100#f1f5f9 | 9.08:1 | AAAA lgAAA | AaAa |
| Slate 200#e2e8f0 | 8.07:1 | AAAA lgAAA | AaAa |
| Slate 300#cbd5e1 | 6.70:1 | AAAA lgAAA | AaAa |
| Slate 400#94a3b8 | 3.88:1 | AAAA lgAAA | AaAa |
| Slate 500#64748b | 2.09:1 | AAAA lgAAA | AaAa |
| Slate 600#475569 | 1.31:1 | AAAA lgAAA | AaAa |
| Slate 700#334155 | 1.04:1 | AAAA lgAAA | AaAa |
| Slate 800#1e293b | 1.47:1 | AAAA lgAAA | AaAa |
| Slate 900#0f172a | 1.80:1 | AAAA lgAAA | AaAa |
| Black#000000 | 2.11:1 | AAAA lgAAA | AaAa |
Roughly one man in twelve has some form of colour vision deficiency. If any of the three panels above is hard to tell apart from a neighbouring colour in your palette, add a shape, an icon or a label so the meaning does not rest on hue alone.
Color scale — 50 to 950
A Tailwind-shaped ramp built around this exact hex. #02437f is pinned to step 900; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.
The same eleven steps expressed in OKLCH, where equal lightness numbers actually look equally spaced. HSL ramps go muddy in the yellows and washed out in the blues; this one does not. Modern browsers render it natively — the hex ramp above is the fallback.
:root {
--brand-50: oklch(0.97 0.029 253.1);
--brand-100: oklch(0.94 0.047 253.1);
--brand-200: oklch(0.88 0.070 253.1);
--brand-300: oklch(0.80 0.091 253.1);
--brand-400: oklch(0.72 0.108 253.1);
--brand-500: oklch(0.64 0.117 253.1);
--brand-600: oklch(0.56 0.117 253.1);
--brand-700: oklch(0.48 0.110 253.1);
--brand-800: oklch(0.40 0.098 253.1);
--brand-900: oklch(0.32 0.082 253.1);
--brand-950: oklch(0.24 0.064 253.1);
}Colors that work with #02437f
Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.
Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.
Lightness flips, hue holds. The accent stays the anchor in both themes.
In real components
The same eight roles, wired into the interface patterns you will actually build with them. Every state below is a computed value, not a mock-up.
Focus ring uses the light variant so the field still reads as one shape.
The file stays available for seven days. Download it before it expires.
How to use #02437f
Derived from its contrast, chroma and lightness — not from taste.
- ✓Body text and links on white
- ✓Primary buttons and calls to action
- ✓Focus rings, active and selected states
- ✓Headers, footers and dark-mode surfaces
- ✓Brand accents, badges and data highlights
- ⚠Text on black or near-black surfaces
- ⚠Full-page backgrounds — tiring over long sessions
- ⚠Black text placed on it
- ⚠Pairing with a same-lightness hue — edges vibrate
Meaning and mood
What a colour in this family tends to signal, and how this particular chroma and lightness change the reading.
The default of institutions for a reason: blue is read as stable and safe across nearly every culture that has been surveyed.
At this chroma the association is amplified — it will dominate anything placed beside it, so give it space and use it sparingly. The low lightness adds weight and formality.
It is also the most crowded hue on the web. Distinctiveness has to come from your other choices.
- FormalityHigh
- EnergyHigh
- Weight75/100
- TemperatureCool
- ApproachabilityReserved
Colour associations are cultural and vary by market. Treat these as a starting point for a conversation with your audience, not a finding about them.
Similar colors
One move away from this hex in each direction. Every swatch is its own page.
Color relationships
The wheel positions with their names attached, so you can grab the one you actually need.
| Complementary | #7F3E02 | Directly opposite — maximum tension | |
| Analogous left | #027F7D | Neighbour, quieter | |
| Analogous right | #02057F | Neighbour, quieter | |
| Split-complement 1 | #7F0205 | Contrast without the clash | |
| Split-complement 2 | #7F7D02 | Contrast without the clash | |
| Triadic 1 | #7F0243 | Even thirds — balanced and loud | |
| Triadic 2 | #437F02 | Even thirds — balanced and loud | |
| Tetradic | #7D027F | Fourth corner of the square scheme |
#02437f sits at 209°. Every dot is a harmony position and links to its own page in the table alongside.
RGB percentages
CMYK percentages
Total ink coverage is 196%. Most commercial presses cap around 300% — above that, sheets stop drying properly.
Color previews
#02437f text on a black background
contrast 2.11:1
#02437f text on a white background
contrast 9.94:1
#02437f on grey
9.08:1
#02437f on its own surface
9.25:1
#02437f on its dark surface
1.73:1
CSS3 live lab
The quick brown fox
color: #02437f;
background-color: #02437f;
Glowing headline
text-shadow: 2px 2px 8px #02437f;
Soft neon halo
text-shadow: 0 0 14px rgba(2, 67, 127, 0.45);
box-shadow: 0 12px 32px -8px rgba(2, 67, 127, 0.45);
border: 3px solid #02437f; background: linear-gradient(135deg, #02437f, #14027F);
Gradient headline
background: linear-gradient(90deg, #02437f, #34027F); -webkit-background-clip: text; color: transparent;
outline: 2px solid #02437f; outline-offset: 3px;
Marked up text
text-decoration-color: #02437f; caret-color: #02437f;
border-left: 4px solid #02437f;
background: #E6F3FF; box-shadow: inset 0 0 0 2px #02437f;
background: conic-gradient(#02437f 68%, #e2e8f0 0);
Transparency
What each alpha value actually composites to. The top row is #02437f over white; the bottom row is the same alpha over a checkerboard, so you can see what survives on a photo or a video.
Bottom row of hexes is the flattened result over white — use those when a design tool refuses transparency, or when you need a solid fallback.
rgba(2, 67, 127, 0.5) rgb(2 67 127 / 50%) #02437f80 hsl(209 97% 25% / 50%) color-mix(in srgb, #02437f 50%, transparent)
| Alpha | 8-digit hex | Flat on white |
|---|---|---|
| 10% | #02437f1a | #E6ECF2 |
| 20% | #02437f33 | #CCD9E5 |
| 40% | #02437f66 | #9AB4CC |
| 60% | #02437f99 | #678EB2 |
| 80% | #02437fcc | #356999 |
Gradients from #02437f
Six recipes, each built from this hex and shown with the exact CSS that produced it.
background: linear-gradient(135deg, #0363BB, #02437f 45%, #02427E);
background: linear-gradient(120deg, #02437f, #170261);
background: linear-gradient(90deg, #02437f, #7F3E02);
background: radial-gradient(120% 120% at 20% 0%, #0373D9 0%, #02437f 45%, #02427E 100%);
background: linear-gradient(180deg, #F4F7FA, #ffffff);
background: radial-gradient(60% 60% at 15% 20%, #03B19F 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #0C029D 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #02427E 0%, transparent 65%), #02437f;
Monochromatic scale
Palettes built from #02437f
Shades — darker
Tints — lighter
Tones — desaturated
Color harmonies
Nearest named colors
Ranked with CIEDE2000 across all 139 CSS keywords. Under ΔE 2 the eye stops telling them apart; over ΔE 10 they are plainly different colors.
Closest color with a full write-up: Classic Blue (Pantone 2020) (#0f4c81) — ΔE2000 3.1 away, with its history, psychology and brand usage.
#02437f in the real world
Where a color in this family tends to land, and the interface roles it is usually asked to play.
Sits outside most CMYK gamuts — expect a duller press result, or specify a spot ink.
Holds up across typical panel gamma. Still worth checking on an uncalibrated laptop, where mid-tones shift most.
Too dim on dark surfaces at 2.11:1 — lift it to #0475DE for body text, or reserve it for fills.
Explore nearby colors
Small, deliberate steps away from this hex — useful when you are hunting for the version of a colour that finally feels right.
#02437f, answered
What color is #02437f?
#02437f is a dark electric blue, closest to Dark Slate Blue (ΔE2000 11.9). It sits at 209° on the hue wheel with 97% saturation and 25% lightness, which reads as cool.
What is the RGB value of #02437f?
rgb(2, 67, 127) — 2 red, 67 green and 127 blue out of 255, or 0.8% / 26.3% / 49.8% by channel.
What is #02437f in HSL and HSV?
hsl(209, 97%, 25%) and hsv(209, 98%, 50%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.
Is #02437f a light or a dark color?
It is a dark color. Relative luminance is 0.0556 and perceived brightness is 26%, so white text on it reaches 9.94:1.
Should I use black or white text on #02437f?
White. It scores 9.94:1 against #02437f, versus 2.11:1 for black — AAA at any size.
Is #02437f accessible on a white background?
#02437f on white scores 9.94:1, which clears AAA at every size.
What is the complementary color of #02437f?
#7F3E02 sits directly opposite on the wheel. Softer options are the split-complements #7F0205 and #7F7D02, which give the same contrast with far less vibration.
What colors go well with #02437f?
For interface work: #F4F7FA as the surface, #C0D7ED for borders, #4B749B for secondary text, #811E00 as an accent and #02427E for hover and pressed states. For a palette, the analogous pair #027F7D and #02057F stays calm, while #7F3E02 is the loudest partner.
What is #02437f in CMYK for printing?
cmyk(98%, 47%, 0%, 50%). This is a screen-to-ink approximation — a color this saturated sits outside most CMYK gamuts and will print duller than it looks here.
Is #02437f warm or cool?
Cool — it scores 99 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #02157F; nudged cooler, #013367.
Which Tailwind color is closest to #02437f?
The slate family — its 500 step is #64748b, ΔE2000 19.4 away. That is a visible difference, so define #02437f as a custom token rather than reaching for the built-in.
How do I use #02437f in Tailwind CSS?
Inline it as an arbitrary value with bg-[#02437f] or text-[#02437f], or register the whole ramp under theme.extend.colors.brand so you get bg-brand-500 and friends. The generated 50–950 scale on this page is ready to paste into your config.
What is #02437f with 50% opacity?
rgba(2, 67, 127, 0.5), or #02437f80 in eight-digit hex. Over white that composites to #81A1BF; over black, #012240.
Is #02437f a web-safe color?
No. The nearest web-safe colour is #003366, ΔE2000 5.6 away. The palette only matters for legacy displays and some email clients now.
What does the color #02437f mean?
As a blue, it reads trusted, calm, competent. The default of institutions for a reason: blue is read as stable and safe across nearly every culture that has been surveyed. At this chroma the effect is amplified — it will dominate whatever sits beside it.
What gradient works with #02437f?
The safest is same-hue elevation: linear-gradient(135deg, #0363BB, #02437f 45%, #02427E). For more colour, a short hue run to #170261 keeps it rich without turning muddy.
Work with #02437f in the Color Lab
Every tool opens with this colour already loaded.
Every value on this page is computed from #02437f at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.