#637eea
a light, electric blue · cool · closest name: Cornflower Blue
Token name suggestion: Drift Denim
#637eea is a light electric blue, 228° on the wheel and 90/100 on the cool side. Put black text on it (5.70:1). As text it scores 3.68:1 on white — large text only. Nearest name is Cornflower Blue, nearest Tailwind family is blue.
At a glance
Every number on this page in one read: what #637eea 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 #637eea.
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 | #637eea |
| HEX (8-digit) | #637eeaff |
| RGB | rgb(99, 126, 234) |
| RGBA | rgba(99, 126, 234, 1) |
| HSL | hsl(228, 76%, 65%) |
| HSV / HSB | hsv(228, 58%, 92%) |
| HWB | hwb(228 39% 8%) |
| CMYK | cmyk(58%, 46%, 0%, 8%) |
| LAB | lab(55.6 21.9 -57.7) |
| LCH | lch(55.6 61.7 290.8) |
| OKLCH | oklch(0.625 0.165 270.5) |
| XYZ (D65) | xyz(27.45, 23.51, 80.92) |
| Decimal | 6520554 |
| Display P3 | color(display-p3 0.388 0.494 0.918) |
| Web-safe | #6666FF |
Copy-ready code
/* CSS */
color: #637eea;
background-color: #637eea;
/* CSS custom property */
--brand: #637eea;
/* Tailwind (arbitrary) */
class="text-[#637eea] bg-[#637eea]"
/* SCSS */
$brand: #637eea;
/* SwiftUI */
Color(red: 0.388, green: 0.494, blue: 0.918)
/* UIKit */
UIColor(red: 0.388, green: 0.494, blue: 0.918, alpha: 1)
/* Android XML */
<color name="brand">#637EEA</color>
/* Android Compose */
Color(0xFF637EEA)
/* Flutter */
Color(0xFF637EEA)
/* Python / OpenCV (BGR) */
(234, 126, 99)
/* Python / PIL (RGB) */
(99, 126, 234)
/* Java AWT */
new Color(99, 126, 234)
/* .NET */
Color.FromArgb(255, 99, 126, 234)
/* OpenGL / Unity (0–1) */
(0.3882f, 0.4941f, 0.9176f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{99,126,234}/* mix without leaving CSS */ background: color-mix(in oklab, #637eea 85%, white); border-color: color-mix(in oklab, #637eea 40%, transparent); /* theme-aware in one line */ color: light-dark(#0F2370, #D3D8EE); /* relative colour syntax */ --hover: hsl(from #637eea h s calc(l - 7));
Design tokens
The same ramp in the four formats a team actually needs. Paste one and the whole palette lands with it.
:root {
--brand-50: #F3F5FC;
--brand-100: #E7EAF9;
--brand-200: #C8D0F4;
--brand-300: #9CADF2;
--brand-400: #637eea;
--brand-500: #395BE4;
--brand-600: #1D42D8;
--brand-700: #1837B4;
--brand-800: #132C90;
--brand-900: #122368;
--brand-950: #0B1641;
--brand: #637eea;
--brand-ink: #000000;
--brand-surface: #F4F6FA;
--brand-border: #C0C9ED;
--brand-hover: #4464E6;
--brand-pressed: #244AE2;
}
@media (prefers-color-scheme: dark) {
:root {
--brand-surface: #141724;
--brand-ink: #D3D8EE;
}
}theme: {
extend: {
colors: {
brand: {
50: '#F3F5FC',
100: '#E7EAF9',
200: '#C8D0F4',
300: '#9CADF2',
400: '#637eea',
500: '#395BE4',
600: '#1D42D8',
700: '#1837B4',
800: '#132C90',
900: '#122368',
950: '#0B1641',
DEFAULT: '#637eea',
},
},
},
}$brand: (
'50': #F3F5FC,
'100': #E7EAF9,
'200': #C8D0F4,
'300': #9CADF2,
'400': #637eea,
'500': #395BE4,
'600': #1D42D8,
'700': #1837B4,
'800': #132C90,
'900': #122368,
'950': #0B1641,
);
$brand-base: #637eea;
$brand-ink: #000000;
@function brand($step) { @return map-get($brand, $step); }{
"color": {
"brand": {
"50": { "$value": "#F3F5FC", "$type": "color" },
"100": { "$value": "#E7EAF9", "$type": "color" },
"200": { "$value": "#C8D0F4", "$type": "color" },
"300": { "$value": "#9CADF2", "$type": "color" },
"400": { "$value": "#637eea", "$type": "color" },
"500": { "$value": "#395BE4", "$type": "color" },
"600": { "$value": "#1D42D8", "$type": "color" },
"700": { "$value": "#1837B4", "$type": "color" },
"800": { "$value": "#132C90", "$type": "color" },
"900": { "$value": "#122368", "$type": "color" },
"950": { "$value": "#0B1641", "$type": "color" }
},
"brandInk": { "$value": "#000000", "$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 #637EEA 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: #637eea as text on that neutral, and that neutral as text on #637eea.
| Neutral | Ratio | Verdict | Both directions |
|---|---|---|---|
| White#ffffff | 3.68:1 | AAAA lgAAA | AaAa |
| Slate 50#f8fafc | 3.52:1 | AAAA lgAAA | AaAa |
| Slate 100#f1f5f9 | 3.36:1 | AAAA lgAAA | AaAa |
| Slate 200#e2e8f0 | 2.99:1 | AAAA lgAAA | AaAa |
| Slate 300#cbd5e1 | 2.48:1 | AAAA lgAAA | AaAa |
| Slate 400#94a3b8 | 1.44:1 | AAAA lgAAA | AaAa |
| Slate 500#64748b | 1.29:1 | AAAA lgAAA | AaAa |
| Slate 600#475569 | 2.06:1 | AAAA lgAAA | AaAa |
| Slate 700#334155 | 2.81:1 | AAAA lgAAA | AaAa |
| Slate 800#1e293b | 3.97:1 | AAAA lgAAA | AaAa |
| Slate 900#0f172a | 4.85:1 | AAAA lgAAA | AaAa |
| Black#000000 | 5.70:1 | 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. #637eea is pinned to step 400; 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 0.041 270.5);
--brand-100: oklch(0.94 0.066 270.5);
--brand-200: oklch(0.88 0.099 270.5);
--brand-300: oklch(0.80 0.128 270.5);
--brand-400: oklch(0.72 0.152 270.5);
--brand-500: oklch(0.64 0.165 270.5);
--brand-600: oklch(0.56 0.165 270.5);
--brand-700: oklch(0.48 0.155 270.5);
--brand-800: oklch(0.40 0.138 270.5);
--brand-900: oklch(0.32 0.115 270.5);
--brand-950: oklch(0.24 0.091 270.5);
}Colors that work with #637eea
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 #637eea
Derived from its contrast, chroma and lightness — not from taste.
- ✓Headings from 24px up on white
- ✓Text and icons on dark surfaces
- ✓Primary buttons and calls to action
- ✓Focus rings, active and selected states
- ✓Card and section backgrounds
- ✓Brand accents, badges and data highlights
- ⚠Small text on white — under 4.5:1
- ⚠Full-page backgrounds — tiring over long sessions
- ⚠White 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 lightness keeps it airy and approachable.
It is also the most crowded hue on the web. Distinctiveness has to come from your other choices.
- FormalityLow
- EnergyHigh
- Weight35/100
- 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 | #EACF63 | Directly opposite — maximum tension | |
| Analogous left | #63C2EA | Neighbour, quieter | |
| Analogous right | #8C63EA | Neighbour, quieter | |
| Split-complement 1 | #EA8C63 | Contrast without the clash | |
| Split-complement 2 | #C2EA63 | Contrast without the clash | |
| Triadic 1 | #EA637E | Even thirds — balanced and loud | |
| Triadic 2 | #7EEA63 | Even thirds — balanced and loud | |
| Tetradic | #EA63C2 | Fourth corner of the square scheme |
#637eea sits at 228°. Every dot is a harmony position and links to its own page in the table alongside.
RGB percentages
CMYK percentages
Total ink coverage is 112%. Most commercial presses cap around 300% — above that, sheets stop drying properly.
Color previews
#637eea text on a black background
contrast 5.70:1
#637eea text on a white background
contrast 3.68:1
#637eea on grey
3.36:1
#637eea on its own surface
3.40:1
#637eea on its dark surface
4.84:1
CSS3 live lab
The quick brown fox
color: #637eea;
background-color: #637eea;
Glowing headline
text-shadow: 2px 2px 8px #637eea;
Soft neon halo
text-shadow: 0 0 14px rgba(99, 126, 234, 0.45);
box-shadow: 0 12px 32px -8px rgba(99, 126, 234, 0.45);
border: 3px solid #637eea; background: linear-gradient(135deg, #637eea, #A263EA);
Gradient headline
background: linear-gradient(90deg, #637eea, #C463EA); -webkit-background-clip: text; color: transparent;
outline: 2px solid #637eea; outline-offset: 3px;
Marked up text
text-decoration-color: #637eea; caret-color: #637eea;
border-left: 4px solid #637eea;
background: #E9ECFC; box-shadow: inset 0 0 0 2px #637eea;
background: conic-gradient(#637eea 68%, #e2e8f0 0);
Transparency
What each alpha value actually composites to. The top row is #637eea 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(99, 126, 234, 0.5) rgb(99 126 234 / 50%) #637eea80 hsl(228 76% 65% / 50%) color-mix(in srgb, #637eea 50%, transparent)
| Alpha | 8-digit hex | Flat on white |
|---|---|---|
| 10% | #637eea1a | #EFF2FD |
| 20% | #637eea33 | #E0E5FB |
| 40% | #637eea66 | #C1CBF7 |
| 60% | #637eea99 | #A1B2F2 |
| 80% | #637eeacc | #8298EE |
Gradients from #637eea
Six recipes, each built from this hex and shown with the exact CSS that produced it.
background: linear-gradient(135deg, #99ABF1, #637eea 45%, #0F2370);
background: linear-gradient(120deg, #637eea, #9F48E6);
background: linear-gradient(90deg, #637eea, #EACF63);
background: radial-gradient(120% 120% at 20% 0%, #B4C1F5 0%, #637eea 45%, #0F2370 100%);
background: linear-gradient(180deg, #F4F6FA, #ffffff);
background: radial-gradient(60% 60% at 15% 20%, #90DBF0 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #A97EEE 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #0F2370 0%, transparent 65%), #637eea;
Monochromatic scale
Palettes built from #637eea
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: Blueberry (#4f86f7) — ΔE2000 4.6 away, with its history, psychology and brand usage.
#637eea 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.
Usable as-is on a dark surface at 5.70:1.
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.
#637eea, answered
What color is #637eea?
#637eea is a light electric blue, closest to Cornflower Blue (ΔE2000 7.8). It sits at 228° on the hue wheel with 76% saturation and 65% lightness, which reads as cool.
What is the RGB value of #637eea?
rgb(99, 126, 234) — 99 red, 126 green and 234 blue out of 255, or 38.8% / 49.4% / 91.8% by channel.
What is #637eea in HSL and HSV?
hsl(228, 76%, 65%) and hsv(228, 58%, 92%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.
Is #637eea a light or a dark color?
It is a mid-tone. Relative luminance is 0.2351 and perceived brightness is 53%, so black text on it reaches 5.70:1.
Should I use black or white text on #637eea?
Black. It scores 5.70:1 against #637eea, versus 3.68:1 for white — AA at any size.
Is #637eea accessible on a white background?
#637eea on white scores 3.68:1, which only clears AA for large text — 18.66px bold or 24px regular and up. Darken it to #4D6BE7 to reach 4.5:1, or #1E44DE for 7:1.
What is the complementary color of #637eea?
#EACF63 sits directly opposite on the wheel. Softer options are the split-complements #EA8C63 and #C2EA63, which give the same contrast with far less vibration.
What colors go well with #637eea?
For interface work: #F4F6FA as the surface, #C0C9ED for borders, #4B5B9B for secondary text, #B86F14 as an accent and #0F2370 for hover and pressed states. For a palette, the analogous pair #63C2EA and #8C63EA stays calm, while #EACF63 is the loudest partner.
What is #637eea in CMYK for printing?
cmyk(58%, 46%, 0%, 8%). 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 #637eea warm or cool?
Cool — it scores 90 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #7A63EA; nudged cooler, #6193EC.
Which Tailwind color is closest to #637eea?
The blue family — its 500 step is #3b82f6, ΔE2000 5.6 away. That is a visible difference, so define #637eea as a custom token rather than reaching for the built-in.
How do I use #637eea in Tailwind CSS?
Inline it as an arbitrary value with bg-[#637eea] or text-[#637eea], 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 #637eea with 50% opacity?
rgba(99, 126, 234, 0.5), or #637eea80 in eight-digit hex. Over white that composites to #B1BFF5; over black, #323F75.
Is #637eea a web-safe color?
No. The nearest web-safe colour is #6666FF, ΔE2000 8.2 away. The palette only matters for legacy displays and some email clients now.
What does the color #637eea 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 #637eea?
The safest is same-hue elevation: linear-gradient(135deg, #99ABF1, #637eea 45%, #0F2370). For more colour, a short hue run to #9F48E6 keeps it rich without turning muddy.
Work with #637eea in the Color Lab
Every tool opens with this colour already loaded.
Every value on this page is computed from #637eea at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.