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#28dfee

a balanced, electric cyan · cool · closest name: Dark Turquoise

RGB
40, 223, 238
HSL
185°, 85%, 55%
CMYK
83, 6, 0, 7
Luminance
0.5940

At a glance

Every number on this page in one read: what #28dfee is made of, how bright it looks, and which way it leans.

Hex
#28dfee
Hue
185°
cyan
Saturation
85%
electric
Lightness
55%
balanced
Brightness
93%
HSV value
Perceived
75%
weighted brightness
Luminance
0.5940
WCAG relative
Temperature
Cool
89/100 cool
Color family
Cyan
Tone
Electric
Best ink
Black
12.88:1
Closest name
Dark Turquoise
ΔE2000 5.9
Where it sits
Hue185° of 360°
Saturation85%
Lightness55%
Temperature
Warm ← → Cool89% cool

Reads cool. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.

Every format

HEX#28dfee
RGBrgb(40, 223, 238)
HSLhsl(185, 85%, 55%)
CMYKcmyk(83%, 6%, 0%, 7%)
LABlab(81.5 -37.4 -19.6)
LCHlch(81.5 42.2 207.7)
OKLCHoklch(0.826 0.135 203.9)
Decimal2678766
Display P3color(display-p3 0.157 0.875 0.933)

Copy-ready code

/* CSS */
color: #28dfee;
background-color: #28dfee;
/* Tailwind (arbitrary) */
class="text-[#28dfee] bg-[#28dfee]"
/* SCSS */
$brand: #28dfee;
/* SwiftUI */
Color(red: 0.157, green: 0.875, blue: 0.933)
/* Android */
Color.parseColor("#28dfee")
/* Flutter */
Color(0xFF28DFEE)
/* Python / OpenCV (BGR) */
(238, 223, 40)

Best text color

Only one of black and white can be right. This is the one, with the number that proves it.

Readable at a glance#000000 on #28dfee · 12.88:1
Use #000000AAA at every size.
Aa
White text · 1.63:1
AA fail · AA large fail · AAA fail
Aa
Black text · 12.88:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #28dfee as text scores 1.63:1 on white and 12.88:1 on black.

Accessibility — WCAG contrast

Aa
#28dfee on white: 1.63:1
AA ✗ fail · AA-large · AAA
Aa
#28dfee on black: 12.88:1
AA ✓ pass · AA-large · AAA
true color
protanopia · #CCD5EF
deuteranopia · #B2C3EF
tritanopia · #00E9E3

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #28dfee 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.

#F2FCFC
#E5F8FA
#C5F3F7
#97F0F7
#63E8F3
#28dfee
#12D3E3
#0FB0BD
#0C8D97
#0D666D
#084044
Base = 500Lightest = 50 · #F2FCFCDarkest = 950 · #084044
:root {
  --brand-50: #F2FCFC;
  --brand-100: #E5F8FA;
  --brand-200: #C5F3F7;
  --brand-300: #97F0F7;
  --brand-400: #63E8F3;
  --brand-500: #28dfee;
  --brand-600: #12D3E3;
  --brand-700: #0FB0BD;
  --brand-800: #0C8D97;
  --brand-900: #0D666D;
  --brand-950: #084044;
  --brand: #28dfee;
  --brand-ink: #000000;
}

Colors that work with #28dfee

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

Text on it#000000
Black wins here
Surface#F4FAFA
Tinted page background
Border#C0E9ED
Hairlines and dividers
Muted text#4B959B
Captions on the surface
Accent#F32348
Second voice, not a rival
Dark variant#096E76
Hover, pressed, headers
Light variant#E7FBFD
Selected rows, tints
Dark surface#142324
Dark-mode background
Light mode
Everything in its place

Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.

Primary actionSecondaryBadge
Dark mode
Same hue, inverted

Lightness flips, hue holds. The accent stays the anchor in both themes.

Primary actionSecondaryAccent

How to use #28dfee

Derived from its contrast, chroma and lightness — not from taste.

Works well for
  • Text and icons on dark surfaces
  • Primary buttons and calls to action
  • Focus rings, active and selected states
  • Brand accents, badges and data highlights
Use with care
  • 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

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#EE3728
Analogous left#28EE9A
Analogous right#287CEE
Split-complement 1#EE287C
Split-complement 2#EE9A28
Triadic 1#EE28DF
Triadic 2#DFEE28
Tetradic#9A28EE

RGB percentages

Red15.7%
Green87.5%
Blue93.3%

CMYK percentages

Cyan83.2%
Magenta6.3%
Yellow0.0%
Key (black)6.7%

Color previews

#28dfee text on a black background

contrast 12.88:1

Card sample

#28dfee text on a white background

contrast 1.63:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #28dfee;
Background color
Panel with #28dfee background
background-color: #28dfee;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #28dfee;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(40, 223, 238, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(40, 223, 238, 0.45);
Border & gradient
Gradient panel
border: 3px solid #28dfee;
background: linear-gradient(135deg, #28dfee, #285BEE);

Monochromatic scale

Palettes built from #28dfee

Shades — darker

Tints — lighter

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.

#28dfee in the real world

Where a color in this family tends to land, and the interface roles it is usually asked to play.

Industries
TechnologyTravelHealthcareMedia
Common UI roles
ButtonsLinksFocus statesCharts
Print note

Sits outside most CMYK gamuts — expect a duller press result, or specify a spot ink.

#28dfee, answered

What color is #28dfee?

#28dfee is a balanced electric cyan, closest to Dark Turquoise (ΔE2000 5.9). It sits at 185° on the hue wheel with 85% saturation and 55% lightness, which reads as cool.

What is the RGB value of #28dfee?

rgb(40, 223, 238) — 40 red, 223 green and 238 blue out of 255, or 15.7% / 87.5% / 93.3% by channel.

Is #28dfee a light or a dark color?

It is a light color. Relative luminance is 0.5940 and perceived brightness is 75%, so black text on it reaches 12.88:1.

Should I use black or white text on #28dfee?

Black. It scores 12.88:1 against #28dfee, versus 1.63:1 for white — AAA at any size.

What is the complementary color of #28dfee?

#EE3728 sits directly opposite on the wheel. Softer options are the split-complements #EE287C and #EE9A28, which give the same contrast with far less vibration.

What colors go well with #28dfee?

For interface work: #F4FAFA as the surface, #C0E9ED for borders, #4B959B for secondary text, #F32348 as an accent and #096E76 for hover and pressed states. For a palette, the analogous pair #28EE9A and #287CEE stays calm, while #EE3728 is the loudest partner.

What is #28dfee in CMYK for printing?

cmyk(83%, 6%, 0%, 7%). 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 #28dfee warm or cool?

Cool — it scores 89 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #28EEB4; nudged cooler, #26B3F0.

Work with #28dfee in the Color Lab