#4fb5df
a balanced, vivid cyan · cool · closest name: Deep Sky Blue
Token name suggestion: Atlas Glacier
#4fb5df is a balanced vivid cyan, 198° on the wheel and 95/100 on the cool side. Put black text on it (9.01:1). As text it scores 2.33:1 on white — use #1E7DA5 instead. Nearest name is Deep Sky Blue, nearest Tailwind family is cyan.
At a glance
Every number on this page in one read: what #4fb5df 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 #4fb5df.
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 | #4fb5df |
| HEX (8-digit) | #4fb5dfff |
| RGB | rgb(79, 181, 223) |
| RGBA | rgba(79, 181, 223, 1) |
| HSL | hsl(198, 69%, 59%) |
| HSV / HSB | hsv(198, 65%, 87%) |
| HWB | hwb(198 31% 13%) |
| CMYK | cmyk(65%, 19%, 0%, 13%) |
| LAB | lab(69.5 -16.9 -29.8) |
| LCH | lch(69.5 34.3 240.5) |
| OKLCH | oklch(0.730 0.112 228.4) |
| XYZ (D65) | xyz(33.06, 40.03, 75.78) |
| Decimal | 5223903 |
| Display P3 | color(display-p3 0.310 0.710 0.875) |
| Web-safe | #66CCCC |
Copy-ready code
/* CSS */
color: #4fb5df;
background-color: #4fb5df;
/* CSS custom property */
--brand: #4fb5df;
/* Tailwind (arbitrary) */
class="text-[#4fb5df] bg-[#4fb5df]"
/* SCSS */
$brand: #4fb5df;
/* SwiftUI */
Color(red: 0.310, green: 0.710, blue: 0.875)
/* UIKit */
UIColor(red: 0.310, green: 0.710, blue: 0.875, alpha: 1)
/* Android XML */
<color name="brand">#4FB5DF</color>
/* Android Compose */
Color(0xFF4FB5DF)
/* Flutter */
Color(0xFF4FB5DF)
/* Python / OpenCV (BGR) */
(223, 181, 79)
/* Python / PIL (RGB) */
(79, 181, 223)
/* Java AWT */
new Color(79, 181, 223)
/* .NET */
Color.FromArgb(255, 79, 181, 223)
/* OpenGL / Unity (0–1) */
(0.3098f, 0.7098f, 0.8745f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{79,181,223}/* mix without leaving CSS */ background: color-mix(in oklab, #4fb5df 85%, white); border-color: color-mix(in oklab, #4fb5df 40%, transparent); /* theme-aware in one line */ color: light-dark(#14526C, #D3E6EE); /* relative colour syntax */ --hover: hsl(from #4fb5df h s calc(l - 7));
Design tokens
The same ramp in the four formats a team actually needs. Paste one and the whole palette lands with it.
:root {
--brand-50: #F3F9FB;
--brand-100: #E7F3F8;
--brand-200: #CAE6F2;
--brand-300: #A0D7EE;
--brand-400: #71C3E5;
--brand-500: #4fb5df;
--brand-600: #269ECF;
--brand-700: #1F83AD;
--brand-800: #19698A;
--brand-900: #164D64;
--brand-950: #0E303F;
--brand: #4fb5df;
--brand-ink: #000000;
--brand-surface: #F4F9FA;
--brand-border: #C0E0ED;
--brand-hover: #31A8D9;
--brand-pressed: #2494C3;
}
@media (prefers-color-scheme: dark) {
:root {
--brand-surface: #142024;
--brand-ink: #D3E6EE;
}
}theme: {
extend: {
colors: {
brand: {
50: '#F3F9FB',
100: '#E7F3F8',
200: '#CAE6F2',
300: '#A0D7EE',
400: '#71C3E5',
500: '#4fb5df',
600: '#269ECF',
700: '#1F83AD',
800: '#19698A',
900: '#164D64',
950: '#0E303F',
DEFAULT: '#4fb5df',
},
},
},
}$brand: (
'50': #F3F9FB,
'100': #E7F3F8,
'200': #CAE6F2,
'300': #A0D7EE,
'400': #71C3E5,
'500': #4fb5df,
'600': #269ECF,
'700': #1F83AD,
'800': #19698A,
'900': #164D64,
'950': #0E303F,
);
$brand-base: #4fb5df;
$brand-ink: #000000;
@function brand($step) { @return map-get($brand, $step); }{
"color": {
"brand": {
"50": { "$value": "#F3F9FB", "$type": "color" },
"100": { "$value": "#E7F3F8", "$type": "color" },
"200": { "$value": "#CAE6F2", "$type": "color" },
"300": { "$value": "#A0D7EE", "$type": "color" },
"400": { "$value": "#71C3E5", "$type": "color" },
"500": { "$value": "#4fb5df", "$type": "color" },
"600": { "$value": "#269ECF", "$type": "color" },
"700": { "$value": "#1F83AD", "$type": "color" },
"800": { "$value": "#19698A", "$type": "color" },
"900": { "$value": "#164D64", "$type": "color" },
"950": { "$value": "#0E303F", "$type": "color" }
},
"brandInk": { "$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 #269ED0 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: #4fb5df as text on that neutral, and that neutral as text on #4fb5df.
| Neutral | Ratio | Verdict | Both directions |
|---|---|---|---|
| White#ffffff | 2.33:1 | AAAA lgAAA | AaAa |
| Slate 50#f8fafc | 2.23:1 | AAAA lgAAA | AaAa |
| Slate 100#f1f5f9 | 2.13:1 | AAAA lgAAA | AaAa |
| Slate 200#e2e8f0 | 1.89:1 | AAAA lgAAA | AaAa |
| Slate 300#cbd5e1 | 1.57:1 | AAAA lgAAA | AaAa |
| Slate 400#94a3b8 | 1.10:1 | AAAA lgAAA | AaAa |
| Slate 500#64748b | 2.04:1 | AAAA lgAAA | AaAa |
| Slate 600#475569 | 3.25:1 | AAAA lgAAA | AaAa |
| Slate 700#334155 | 4.44:1 | AAAA lgAAA | AaAa |
| Slate 800#1e293b | 6.27:1 | AAAA lgAAA | AaAa |
| Slate 900#0f172a | 7.66:1 | AAAA lgAAA | AaAa |
| Black#000000 | 9.01:1 | 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. #4fb5df is pinned to step 500; 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 0.028 228.4);
--brand-100: oklch(0.94 0.045 228.4);
--brand-200: oklch(0.88 0.067 228.4);
--brand-300: oklch(0.80 0.087 228.4);
--brand-400: oklch(0.72 0.103 228.4);
--brand-500: oklch(0.64 0.112 228.4);
--brand-600: oklch(0.56 0.112 228.4);
--brand-700: oklch(0.48 0.105 228.4);
--brand-800: oklch(0.40 0.094 228.4);
--brand-900: oklch(0.32 0.078 228.4);
--brand-950: oklch(0.24 0.061 228.4);
}Colors that work with #4fb5df
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 #4fb5df
Derived from its contrast, chroma and lightness — not from taste.
- ✓Text and icons on dark surfaces
- ✓Primary buttons and calls to action
- ✓Focus rings, active and selected states
- ✓Brand accents, badges and data highlights
- ✓Chart series and data categories
- ⚠Text of any size on white — fails WCAG AA
- ⚠Full-page backgrounds — tiring over long sessions
- ⚠Thin strokes and 1px borders — they disappear on light UI
- ⚠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.
Cyan reads as water, air and infrastructure: cool, hygienic, engineered.
This is a confident chroma: strong enough to lead a brand, restrained enough to live in an interface all day. The mid lightness keeps it versatile in both themes.
At high lightness it disappears into white surfaces and thin strokes vanish entirely.
- FormalityMedium
- EnergyMedium-high
- Weight41/100
- 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 | #DF794F | Directly opposite — maximum tension | |
| Analogous left | #4FDFC1 | Neighbour, quieter | |
| Analogous right | #4F6DDF | Neighbour, quieter | |
| Split-complement 1 | #DF4F6D | Contrast without the clash | |
| Split-complement 2 | #DFC14F | Contrast without the clash | |
| Triadic 1 | #DF4FB5 | Even thirds — balanced and loud | |
| Triadic 2 | #B5DF4F | Even thirds — balanced and loud | |
| Tetradic | #C14FDF | Fourth corner of the square scheme |
#4fb5df sits at 198°. Every dot is a harmony position and links to its own page in the table alongside.
RGB percentages
CMYK percentages
Total ink coverage is 96%. Most commercial presses cap around 300% — above that, sheets stop drying properly.
Color previews
#4fb5df text on a black background
contrast 9.01:1
#4fb5df text on a white background
contrast 2.33:1
#4fb5df on grey
2.13:1
#4fb5df on its own surface
2.20:1
#4fb5df on its dark surface
7.14:1
CSS3 live lab
The quick brown fox
color: #4fb5df;
background-color: #4fb5df;
Glowing headline
text-shadow: 2px 2px 8px #4fb5df;
Soft neon halo
text-shadow: 0 0 14px rgba(79, 181, 223, 0.45);
box-shadow: 0 12px 32px -8px rgba(79, 181, 223, 0.45);
border: 3px solid #4fb5df; background: linear-gradient(135deg, #4fb5df, #4F55DF);
Gradient headline
background: linear-gradient(90deg, #4fb5df, #6D4FDF); -webkit-background-clip: text; color: transparent;
outline: 2px solid #4fb5df; outline-offset: 3px;
Marked up text
text-decoration-color: #4fb5df; caret-color: #4fb5df;
border-left: 4px solid #4fb5df;
background: #E9F6FB; box-shadow: inset 0 0 0 2px #4fb5df;
background: conic-gradient(#4fb5df 68%, #e2e8f0 0);
Transparency
What each alpha value actually composites to. The top row is #4fb5df 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(79, 181, 223, 0.5) rgb(79 181 223 / 50%) #4fb5df80 hsl(198 69% 59% / 50%) color-mix(in srgb, #4fb5df 50%, transparent)
| Alpha | 8-digit hex | Flat on white |
|---|---|---|
| 10% | #4fb5df1a | #EDF8FC |
| 20% | #4fb5df33 | #DCF0F9 |
| 40% | #4fb5df66 | #B9E1F2 |
| 60% | #4fb5df99 | #95D3EC |
| 80% | #4fb5dfcc | #72C4E5 |
Gradients from #4fb5df
Six recipes, each built from this hex and shown with the exact CSS that produced it.
background: linear-gradient(135deg, #83CBE8, #4fb5df 45%, #14526C);
background: linear-gradient(120deg, #4fb5df, #3C35DA);
background: linear-gradient(90deg, #4fb5df, #DF794F);
background: radial-gradient(120% 120% at 20% 0%, #9DD6ED 0%, #4fb5df 45%, #14526C 100%);
background: linear-gradient(180deg, #F4F9FA, #ffffff);
background: radial-gradient(60% 60% at 15% 20%, #7AE7C7 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #6978E4 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #14526C 0%, transparent 65%), #4fb5df;
Monochromatic scale
Palettes built from #4fb5df
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: Sky Blue (#87ceeb) — ΔE2000 8.1 away, with its history, psychology and brand usage.
#4fb5df in the real world
Where a color in this family tends to land, and the interface roles it is usually asked to play.
Converts to four-color process without much drama. Proof it anyway.
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 9.01:1.
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.
#4fb5df, answered
What color is #4fb5df?
#4fb5df is a balanced vivid cyan, closest to Deep Sky Blue (ΔE2000 5). It sits at 198° on the hue wheel with 69% saturation and 59% lightness, which reads as cool.
What is the RGB value of #4fb5df?
rgb(79, 181, 223) — 79 red, 181 green and 223 blue out of 255, or 31% / 71% / 87.5% by channel.
What is #4fb5df in HSL and HSV?
hsl(198, 69%, 59%) and hsv(198, 65%, 87%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.
Is #4fb5df a light or a dark color?
It is a mid-tone. Relative luminance is 0.4004 and perceived brightness is 64%, so black text on it reaches 9.01:1.
Should I use black or white text on #4fb5df?
Black. It scores 9.01:1 against #4fb5df, versus 2.33:1 for white — AAA at any size.
Is #4fb5df accessible on a white background?
#4fb5df on white scores 2.33:1, which fails WCAG AA at every size. Darken it to #1E7DA5 to reach 4.5:1, or #165D7A for 7:1.
What is the complementary color of #4fb5df?
#DF794F sits directly opposite on the wheel. Softer options are the split-complements #DF4F6D and #DFC14F, which give the same contrast with far less vibration.
What colors go well with #4fb5df?
For interface work: #F4F9FA as the surface, #C0E0ED for borders, #4B839B for secondary text, #E3514B as an accent and #14526C for hover and pressed states. For a palette, the analogous pair #4FDFC1 and #4F6DDF stays calm, while #DF794F is the loudest partner.
What is #4fb5df in CMYK for printing?
cmyk(65%, 19%, 0%, 13%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.
Is #4fb5df warm or cool?
Cool — it scores 95 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #4FDFD4; nudged cooler, #4DA2E1.
Which Tailwind color is closest to #4fb5df?
The cyan family — its 500 step is #06b6d4, ΔE2000 6.2 away. That is a visible difference, so define #4fb5df as a custom token rather than reaching for the built-in.
How do I use #4fb5df in Tailwind CSS?
Inline it as an arbitrary value with bg-[#4fb5df] or text-[#4fb5df], 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 #4fb5df with 50% opacity?
rgba(79, 181, 223, 0.5), or #4fb5df80 in eight-digit hex. Over white that composites to #A7DAEF; over black, #285B70.
Is #4fb5df a web-safe color?
No. The nearest web-safe colour is #66CCCC, ΔE2000 15.3 away. The palette only matters for legacy displays and some email clients now.
What does the color #4fb5df mean?
As a cyan, it reads clean, technical, fresh. Cyan reads as water, air and infrastructure: cool, hygienic, engineered. At this chroma the effect is amplified — it will dominate whatever sits beside it.
What gradient works with #4fb5df?
The safest is same-hue elevation: linear-gradient(135deg, #83CBE8, #4fb5df 45%, #14526C). For more colour, a short hue run to #3C35DA keeps it rich without turning muddy.
Work with #4fb5df in the Color Lab
Every tool opens with this colour already loaded.
Every value on this page is computed from #4fb5df at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.