#66B5FF Color

#66B5FF is rgb(102, 181, 255) in RGB, hsl(209, 100%, 70%) in HSL, and about cmyk(60%, 29%, 0%, 0%) in CMYK. It has no registered color name of its own — the closest is French Sky Blue (#77B5FE), very hard to tell apart at ΔE 3.99. Black text is the more readable choice on this background.

#66B5FF

HEX#66B5FF

RGBrgb(102, 181, 255)

HSLhsl(209, 100%, 70%)

HSVhsv(209, 60%, 100%)

CMYKcmyk(60%, 29%, 0%, 0%)

OKLCHoklch(75.3% 0.133 248.6)

LABlab(70.97% -8.62 -44.72)

LCHlch(70.97% 45.54 259.08)

What #66B5FF 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 #66B5FF, ordered by CIE76 distance in CIELAB. Anything under about ΔE 2 is a difference most people cannot see.

French Sky Blue#77B5FEΔE 3.99 Very Light Azure#74BBFBΔE 6.02 Blue Jeans#5DADECΔE 6.58 Maya Blue#73C2FBΔE 10.47 Little Boy Blue#6CA0DCΔE 11.38 Microsoft Blue#00A2EDΔE 11.39

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

#66B5FF Channel Values

How #66B5FF 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 102 · G 181 · B 255	8-bit channels as sent to the display
HSL	H 209° · S 100% · L 70%	Easiest model for building lighter and darker variants
HSV	H 209° · S 60% · V 100%	Matches the picker in most design tools
CMYK	C 60% · M 29% · Y 0% · K 0%	Approximate ink mix; confirm with an ICC profile before printing
Luminance	2.18:1 vs white · 9.62:1 vs black	WCAG 2.2 relative-luminance contrast ratios

Text Contrast & Accessibility

WCAG 2.2 contrast ratios for text on a #66B5FF 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 text2.18:1AA normal AA large AAA normal

TextBlack text9.62:1AA normal AA large AAA normal

Need a specific ratio against another background? Open #66B5FF in the contrast checker.

Colors That Go With #66B5FF

Pairings derived from color-wheel relationships. The complementary color sits opposite #66B5FF; 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 #66B5FF

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 #66B5FF.

How #66B5FF 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#66B5FF

Protanopia#ABABFF

Protanomaly#94AFFF

Deuteranopia#A0A0FF

Deuteranomaly#8DA9FF

Tritanopia#48C0C0

Tritanomaly#55BCDC

Achromatopsia#AFAFAF

Test a full palette in the color blindness simulator.

Using #66B5FF in Code

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

CSS custom property--color-66b5ff: #66B5FF;

CSS backgroundbackground-color: #66B5FF;

Tailwind configcolors: { 'color-66b5ff': '#66B5FF' }

SwiftUIColor(red: 0.400, green: 0.710, blue: 1.000)

Android XML<color name="color_66b5ff">#66B5FF</color>

SVG fillfill="#66B5FF"

More Blue Colors

#66B5FF 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

#66B5FF Frequently Asked Questions

What color is #66B5FF?

#66B5FF is a light blue — rgb(102, 181, 255) in RGB and hsl(209, 100%, 70%) in HSL. It carries no registered color name of its own; the closest named color is French Sky Blue (#77B5FE), which is very hard to tell apart at a CIE76 distance of 3.99.

What is the RGB value of #66B5FF?

#66B5FF is rgb(102, 181, 255) — red 102, green 181, and blue 255 on the 0-255 scale.

What is the CMYK value of #66B5FF?

#66B5FF converts to approximately cmyk(60%, 29%, 0%, 0%). CMYK output is a mathematical approximation for planning; confirm production print colors with your printer and ICC profile.

Should text on #66B5FF be black or white?

Black text is the more readable choice. #66B5FF scores 2.18:1 against white and 9.62:1 against black, and WCAG 2.2 asks for at least 4.5:1 for normal body text.

Can I write #66B5FF as a CSS color keyword?

No. #66B5FF 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 15.51, which is visibly different.

Open #66B5FF 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.