Rich Cerulean Blue
A vivid, cool dark blue.
#123FB7
rgb(18, 63, 183)
Color formats
HEX
#123FB7
RGB
rgb(18, 63, 183)
HSL
hsl(223.6, 82.1%, 39.4%)
HSV
hsv(223.6, 90.2%, 71.8%)
CMYK
cmyk(90.2%, 65.6%, 0%, 28.2%)
Color shades
Lighter tints and darker shades of Rich Cerulean Blue.
Lightest
#9FB7F6
Lighter
#4271EC
Base
#123FB7
Darker
#091F5A
Darkest
#000000
Complementary
The opposite hue on the color wheel.
Analogous
Neighbouring hues that harmonise.
Contrast & readability
Where Rich Cerulean Blue works
Rich Cerulean Blue (#123FB7) is a vivid, cool dark blue. Its mid-range lightness makes it a flexible choice for buttons, fills and accents that need to read clearly without overpowering a layout. Its cool undertone lends a calm, trustworthy feel that suits clean, professional interfaces.
Observe the spectrum
More colors related to Rich Cerulean Blue — or browse all blues.
Color tools
Color Format Converter
Convert any color between HEX, RGB, HSL, HSV, CMYK and OKLCH instantly — and copy ready-to-paste CSS, SCSS or Tailwind.
Color Picker
Pick any color visually and copy accurate HEX, RGB, HSL and CMYK codes — no signup.
Palette Generator
Generate harmonious color palettes from any base color — complementary, analogous, triadic and more, with instant CSS export.
Contrast Checker
Test color contrast against WCAG 2.1 AA/AAA — live pass/fail, font-size rules, and a real component preview.
Shade & Tint Generator
Generate 10–12 step tints and shades from any color — perfect 50–950 UI ramps with CSS and Tailwind export.
Complementary Color Finder
Find the perfect complementary (180° opposite) color for any shade, with HEX/RGB/HSL and contrast info.