#51AEFB Color

#51AEFB is rgb(81, 174, 251) in RGB, hsl(207, 96%, 65%) in HSL, and about cmyk(68%, 31%, 0%, 2%) in CMYK. It has no registered color name of its own — the closest is French Sky Blue (#77B5FE), clearly related but distinguishable side by side at ΔE 7.49. Black text is the more readable choice on this background.

#51AEFB

HEX#51AEFB

RGBrgb(81, 174, 251)

HSLhsl(207, 96%, 65%)

HSVhsv(207, 68%, 98%)

CMYKcmyk(68%, 31%, 0%, 2%)

OKLCHoklch(72.8% 0.143 246.5)

LABlab(68.04% -10.06 -47.21)

LCHlch(68.04% 48.27 257.97)

What #51AEFB Is Called

Most hex codes have no name: there are 16.7 million of them and a few thousand registered names. These are the named colors nearest to #51AEFB, ordered by CIE76 distance in CIELAB. Anything under about ΔE 2 is a difference most people cannot see.

French Sky Blue#77B5FEΔE 7.49 Blue Jeans#5DADECΔE 7.64 Microsoft Blue#00A2EDΔE 7.73 Very Light Azure#74BBFBΔE 9.53 Vivid Cerulean#00AAEEΔE 9.69 Little Boy Blue#6CA0DCΔE 12.55

Browse the full index of named colors A-Z or every blue in the library.

#51AEFB Channel Values

How #51AEFB breaks down in each color model. Hue is measured in degrees around the color wheel; saturation, lightness, and the CMYK inks are percentages.

Model	Channels	Notes
RGB	R 81 · G 174 · B 251	8-bit channels as sent to the display
HSL	H 207° · S 96% · L 65%	Easiest model for building lighter and darker variants
HSV	H 207° · S 68% · V 98%	Matches the picker in most design tools
CMYK	C 68% · M 31% · Y 0% · K 2%	Approximate ink mix; confirm with an ICC profile before printing
Luminance	2.39:1 vs white · 8.8:1 vs black	WCAG 2.2 relative-luminance contrast ratios

Text Contrast & Accessibility

WCAG 2.2 contrast ratios for text on a #51AEFB background. AA requires 4.5:1 for normal text and 3:1 for large text; AAA requires 7:1. Contrast is one check, not a full accessibility review.

Fails AAWhite text2.39:1AA normal AA large AAA normal

TextBlack text8.8:1AA normal AA large AAA normal

Need a specific ratio against another background? Open #51AEFB in the contrast checker.

Colors That Go With #51AEFB

Pairings derived from color-wheel relationships. The complementary color sits opposite #51AEFB; analogous colors sit beside it; triadic and split-complementary sets spread evenly around the wheel. Select any swatch for its own breakdown.

Base

Complementary

Analogous

Analogous

Triadic

Triadic

Split comp.

Split comp.

Tints & Shades of #51AEFB

Lighter tints and darker shades built by moving the lightness channel while holding hue and saturation, which is what you want for hover states, backgrounds, and text variants.

Tints

Shades

Want a full 50-950 ramp with semantic roles? Generate design tokens from #51AEFB.

How #51AEFB Looks with Color Vision Deficiency

Simulated with the Viénot, Brettel & Mollon LMS projection model. Anomalous types are rendered as partial versions of the matching dichromacy, which is an approximation rather than a per-person clinical model.

Typical#51AEFB

Protanopia#A3A3FB

Protanomaly#89A7FB

Deuteranopia#9797FC

Deuteranomaly#81A1FC

Tritanopia#1EBABA

Tritanomaly#39B5D7

Achromatopsia#A8A8A8

Test a full palette in the color blindness simulator.

Using #51AEFB in Code

Copy-ready declarations for the places this color usually ends up.

CSS custom property--color-51aefb: #51AEFB;

CSS backgroundbackground-color: #51AEFB;

Tailwind configcolors: { 'color-51aefb': '#51AEFB' }

SwiftUIColor(red: 0.318, green: 0.682, blue: 0.984)

Android XML<color name="color_51aefb">#51AEFB</color>

SVG fillfill="#51AEFB"

More Blue Colors

#51AEFB sits in the blue family. These are its neighbours across that family's full range, each with its own breakdown.

000024 fafaff 00002e f9fafb 000033 f8fafc 000038 f8f8ff 000042 f5faff 000047 f5f5ff 002147 007dfa 0f52ba 1c39bb 2a3439 372aac 4e3cc3 64609a 7abdff 979aaa b8dbff d6d6ff

#51AEFB Frequently Asked Questions

What color is #51AEFB?

#51AEFB is a light blue — rgb(81, 174, 251) in RGB and hsl(207, 96%, 65%) in HSL. It carries no registered color name of its own; the closest named color is French Sky Blue (#77B5FE), which is clearly related but distinguishable side by side at a CIE76 distance of 7.49.

What is the RGB value of #51AEFB?

#51AEFB is rgb(81, 174, 251) — red 81, green 174, and blue 251 on the 0-255 scale.

What is the CMYK value of #51AEFB?

#51AEFB converts to approximately cmyk(68%, 31%, 0%, 2%). CMYK output is a mathematical approximation for planning; confirm production print colors with your printer and ICC profile.

Should text on #51AEFB be black or white?

Black text is the more readable choice. #51AEFB scores 2.39:1 against white and 8.8:1 against black, and WCAG 2.2 asks for at least 4.5:1 for normal body text.

Can I write #51AEFB as a CSS color keyword?

No. #51AEFB is not one of the CSS color keywords, so it has to be written as a hex, rgb() or hsl() value. The closest keyword is deepskyblue (#00BFFF) at a CIE76 distance of 14.96, which is visibly different.

Open #51AEFB in a Tool

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Keep exploring: every blue in the color library, the guide to shades of blue, or the full color library.