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Electrifying Tetsukon

#3a9bdf
Notes

Electrifying Tetsukon (#3A9BDF) is a true azure with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (205°, 72%, 55%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. For a confident two-color system, pair it with its complementary orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#3a9bdf
RGB
rgb(58, 155, 223)
HSL
hsl(205, 72%, 55%)
HWB
hwb(205 23% 13%)
OKLCH
oklch(66.4% 0.135 243.4)
P3
color(display-p3 0.3371 0.5998 0.8523)
HSV
hsv(205, 74%, 87%)
LAB
lab(61.37% -5.68 -42.54)
LCH
lch(61.37% 42.92 262.39)
CMYK
cmyk(74%, 30%, 0%, 13%)

Etymology

Electrifying
adjective

Greek ēléktron, amber — present-participle of electrify, named after the static-electricity property of rubbed amber. As a color modifier, electrifying implies a saturated-and-shocking-and-active quality, the bright color of Tesla-coil high-voltage atmospheric-discharge emission. Sits at the bright-and-active end of the grid, parallel to charged and neon in usage.

Tetsukon
noun

Japanese tetsukon (鉄紺) — iron navy, the saturated dark blue of Meiji-period samurai ceremonial robes and the kasuri (ikat) textiles of pre-modern rural Japan. The color refers to a tetsukon-dyed kasuri cotton: a deep, slightly cool dark blue with the matte finish of multi-bath dyed cotton.

Closest matches

The nearest named color in three reference sources, ranked by perceptual distance (ΔE76 in CIELAB). ΔE < 1 is imperceptible to most viewers; ΔE > 10 is clearly different. When two sources point to the same hex they’re merged into one tile; click any to open that color’s page.

Variations

Click any swatch to explore

Harmonies

Accessibility

Color-vision simulation

How this color appears to viewers with the four major color-vision-deficiency types. Computed via the Machado (2009) physiologically-based model. If a tile matches the original, the color reads the same to that viewer.

#3a9bdf
Original
#7c9de2
Protanopia
#658dde
Deuteranopia
#00acb3
Tritanopia
#8b8b8b
Achromatopsia
WCAG contrast

The color used as foreground text against pure white and pure black, with the contrast ratio and WCAG 2.1 grade. Aim for AA (4.5:1) for body text and AA Large (3:1) for 18 pt+ headlines; AAA (7:1) is the gold standard for long-form reading surfaces.

The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon White
3.03:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAon Black
6.93:1

Wide gamut

Display P3 representation

The CSS Color 4 wide-gamut form of this color. Both swatches render the same color on every display — the P3 form only diverges from sRGB when a designer pushes channels outside sRGB's reach.

sRGB hex
sRGB hex
##3A9BDF
Display P3
Display P3
color(display-p3 0.3371 0.5998 0.8523)
P3 has subtle headroomOKLCH chroma 0.135

Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.

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