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Ultramarine #3f00ff

The blue that cost more than gold.

RGB
63, 0, 255
HSL
255°, 100%, 50%
CMYK
75, 100, 0, 0
Luminance
0.0828

About Ultramarine

Ultramarine, #3f00ff, is blue pushed toward violet — historically the most expensive color ever sold. Ground from Afghan lapis lazuli and shipped “beyond the sea” (ultra marinus), it was priced by the carat and rationed by contract.

History

Renaissance patrons specified ultramarine by weight in painting contracts — reserved for the Virgin’s robe because nothing else was worthy of the cost. Synthetic ultramarine (1826, prize-winning) democratized it overnight; Yves Klein then patented his own matte version, IKB, and painted everything.

Psychology

Ultramarine is depth itself — blue at maximum sincerity, leaning violet toward the spiritual. Klein chose it precisely because it seemed to open into space rather than sit on a surface.

In design

Ultramarine electrifies as accents and art-directed heroes; #3f00ff is display-only on white (large text at best). Its usable descendants are the indigo UI family. Pair with white for gallery starkness, gold for Renaissance quotes, warm gray to calm it.

In culture

IKB, lapis manuscripts, “ultramarine” as poetry’s deepest blue: the pigment’s price wrote centuries of art history — where blue appears in old masters, budget decisions appear too.

Brands that own ultramarine

Shades of ultramarine

Every format

HEX#3f00ff
RGBrgb(63, 0, 255)
HSLhsl(255, 100%, 50%)
CMYKcmyk(75%, 100%, 0%, 0%)
LABlab(34.5 80.0 -104.0)
LCHlch(34.5 131.2 307.6)
OKLCHoklch(0.473 0.301 273.6)

Copy-ready code

/* CSS */
color: #3f00ff;
background-color: #3f00ff;
/* Tailwind (arbitrary) */
class="text-[#3f00ff] bg-[#3f00ff]"
/* SCSS */
$brand: #3f00ff;
/* SwiftUI */
Color(red: 0.247, green: 0.000, blue: 1.000)
/* Android */
Color.parseColor("#3f00ff")

Accessibility — WCAG contrast

Aa
#3f00ff on white: 7.91:1
AA ✓ pass · AA-large · AAA
Aa
#3f00ff on black: 2.66:1
AA ✗ fail · AA-large · AAA
true color
protanopia
deuteranopia
tritanopia

RGB percentages

Red24.7%
Green0.0%
Blue100.0%

CMYK percentages

Cyan75.3%
Magenta100.0%
Yellow0.0%
Key (black)0.0%

Color previews

#3f00ff text on a black background

contrast 2.66:1

Card sample

#3f00ff text on a white background

contrast 7.91:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #3f00ff;
Background color
Panel with #3f00ff background
background-color: #3f00ff;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #3f00ff;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(63, 0, 255, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(63, 0, 255, 0.45);
Border & gradient
Gradient panel
border: 3px solid #3f00ff;
background: linear-gradient(135deg, #3f00ff, #E900FF);

Monochromatic scale

Palettes built from #3f00ff

Shades — darker

Tints — lighter

Hue & tone neighbors

Color harmonies

Nearest named colors

Ultramarine, answered

What is the hex code for ultramarine?

Ultramarine is #3f00ff (violet-leaning); historical lapis pigment photographs near #26619c; Klein’s IKB is #002fa7.

Why was ultramarine so expensive?

One source (Afghan lapis mines), brutal extraction, and sea-trade logistics — costs stacked until the pigment out-priced gold. Contracts literally specified how much the painter could use.

What is International Klein Blue?

Yves Klein’s 1960 matte ultramarine formulation (#002fa7) — pigment suspended in a binder that keeps its raw-powder depth. He registered the recipe and made the color itself the artwork.

Work with #3f00ff in the Color Lab