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#2a7ddf

a balanced, vivid blue · cool · closest name: Steel Blue

RGB
42, 125, 223
HSL
213°, 74%, 52%
CMYK
81, 44, 0, 13
Luminance
0.2049

At a glance

Every number on this page in one read: what #2a7ddf is made of, how bright it looks, and which way it leans.

Hex
#2a7ddf
Hue
213°
blue
Saturation
74%
vivid
Lightness
52%
balanced
Brightness
87%
HSV value
Perceived
49%
weighted brightness
Luminance
0.2049
WCAG relative
Temperature
Cool
99/100 cool
Color family
Blue
Tone
Vivid
Best ink
Black
5.10:1
Closest name
Steel Blue
ΔE2000 4.9
Where it sits
Hue213° of 360°
Saturation74%
Lightness52%
Temperature
Warm ← → Cool99% 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#2a7ddf
RGBrgb(42, 125, 223)
HSLhsl(213, 74%, 52%)
CMYKcmyk(81%, 44%, 0%, 13%)
LABlab(52.4 10.4 -56.8)
LCHlch(52.4 57.8 280.4)
OKLCHoklch(0.592 0.169 255.3)
Decimal2784735
Display P3color(display-p3 0.165 0.490 0.875)

Copy-ready code

/* CSS */
color: #2a7ddf;
background-color: #2a7ddf;
/* Tailwind (arbitrary) */
class="text-[#2a7ddf] bg-[#2a7ddf]"
/* SCSS */
$brand: #2a7ddf;
/* SwiftUI */
Color(red: 0.165, green: 0.490, blue: 0.875)
/* Android */
Color.parseColor("#2a7ddf")
/* Flutter */
Color(0xFF2A7DDF)
/* Python / OpenCV (BGR) */
(223, 125, 42)

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 #2a7ddf · 5.10:1
Use #000000AA at every size, AAA for large text only.
Aa
White text · 4.12:1
AA fail · AA large pass · AAA fail
Aa
Black text · 5.10:1 · recommended
AA pass · AA large pass · AAA fail
Reading the other direction: #2a7ddf as text scores 4.12:1 on white and 5.10:1 on black.

Accessibility — WCAG contrast

Aa
#2a7ddf on white: 4.12:1
AA ✗ fail · AA-large · AAA
Aa
#2a7ddf on black: 5.10:1
AA ✓ pass · AA-large · AAA
true color
protanopia · #4A86E3
deuteranopia · #2375DD
tritanopia · #0094A3

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #2a7ddf 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.

#F3F7FC
#E7EFF9
#C8DCF3
#9DC3F0
#6DA6E9
#2a7ddf
#2073D5
#1B60B1
#154D8E
#143A67
#0C2440
Base = 500Lightest = 50 · #F3F7FCDarkest = 950 · #0C2440
:root {
  --brand-50: #F3F7FC;
  --brand-100: #E7EFF9;
  --brand-200: #C8DCF3;
  --brand-300: #9DC3F0;
  --brand-400: #6DA6E9;
  --brand-500: #2a7ddf;
  --brand-600: #2073D5;
  --brand-700: #1B60B1;
  --brand-800: #154D8E;
  --brand-900: #143A67;
  --brand-950: #0C2440;
  --brand: #2a7ddf;
  --brand-ink: #000000;
}

Colors that work with #2a7ddf

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#F4F7FA
Tinted page background
Border#C0D4ED
Hairlines and dividers
Muted text#4B6F9B
Captions on the surface
Accent#E45D25
Second voice, not a rival
Dark variant#113C6F
Hover, pressed, headers
Light variant#E9F1FC
Selected rows, tints
Dark surface#141B24
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 #2a7ddf

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

Works well for
  • Headings from 24px up on white
  • 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
  • Small text on white — under 4.5:1
  • Full-page backgrounds — tiring over long sessions
  • 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#DF8C2A
Analogous left#2AD8DF
Analogous right#322ADF
Split-complement 1#DF322A
Split-complement 2#D8DF2A
Triadic 1#DF2A7D
Triadic 2#7DDF2A
Tetradic#DF2AD8

RGB percentages

Red16.5%
Green49.0%
Blue87.5%

CMYK percentages

Cyan81.2%
Magenta43.9%
Yellow0.0%
Key (black)12.5%

Color previews

#2a7ddf text on a black background

contrast 5.10:1

Card sample

#2a7ddf text on a white background

contrast 4.12:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #2a7ddf;
Background color
Panel with #2a7ddf background
background-color: #2a7ddf;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #2a7ddf;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(42, 125, 223, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(42, 125, 223, 0.45);
Border & gradient
Gradient panel
border: 3px solid #2a7ddf;
background: linear-gradient(135deg, #2a7ddf, #502ADF);

Monochromatic scale

Palettes built from #2a7ddf

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.

#2a7ddf in the real world

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

Industries
TechnologyFinanceHealthcareEnterprise SaaS
Common UI roles
ButtonsLinksFocus statesCharts
Print note

Converts to four-color process without much drama. Proof it anyway.

#2a7ddf, answered

What color is #2a7ddf?

#2a7ddf is a balanced vivid blue, closest to Steel Blue (ΔE2000 4.9). It sits at 213° on the hue wheel with 74% saturation and 52% lightness, which reads as cool.

What is the RGB value of #2a7ddf?

rgb(42, 125, 223) — 42 red, 125 green and 223 blue out of 255, or 16.5% / 49% / 87.5% by channel.

Is #2a7ddf a light or a dark color?

It is a mid-tone. Relative luminance is 0.2049 and perceived brightness is 49%, so black text on it reaches 5.10:1.

Should I use black or white text on #2a7ddf?

Black. It scores 5.10:1 against #2a7ddf, versus 4.12:1 for white — AA at any size.

What is the complementary color of #2a7ddf?

#DF8C2A sits directly opposite on the wheel. Softer options are the split-complements #DF322A and #D8DF2A, which give the same contrast with far less vibration.

What colors go well with #2a7ddf?

For interface work: #F4F7FA as the surface, #C0D4ED for borders, #4B6F9B for secondary text, #E45D25 as an accent and #113C6F for hover and pressed states. For a palette, the analogous pair #2AD8DF and #322ADF stays calm, while #DF8C2A is the loudest partner.

What is #2a7ddf in CMYK for printing?

cmyk(81%, 44%, 0%, 13%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #2a7ddf warm or cool?

Cool — it scores 99 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #2A3BDF; nudged cooler, #1D71D3.

Work with #2a7ddf in the Color Lab