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Firm Polemonium

#303b9a
Notes

Firm Polemonium (#303B9A) is a true blue with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (234°, 52%, 40%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#303b9a
RGB
rgb(48, 59, 154)
HSL
hsl(234, 52%, 40%)
HWB
hwb(234 19% 40%)
OKLCH
oklch(40.4% 0.154 272.4)
P3
color(display-p3 0.1967 0.2301 0.5820)
HSV
hsv(234, 69%, 60%)
LAB
lab(29.63% 27.89 -53.30)
LCH
lch(29.63% 60.15 297.62)
CMYK
cmyk(69%, 62%, 0%, 40%)

Etymology

Firm
adjective

Latin firmus, strong / stable — sharing root with English farm (originally a fixed-yearly-rental). As a color modifier, firm implies a saturated-and-resolute quality where the hue holds its visual position without wavering. Sits at the bold-and-firm end of the grid, parallel to steadfast and unwavering in usage.

Polemonium
noun

The genus PolemoniumJacob's ladder, the European and North American rock-garden perennial whose pinnate ladder-shaped foliage and clusters of blue flowers appear in late spring. The color refers to a fresh P. caeruleum in flower: a saturated, slightly cool deep blue with the matte finish of small five-petaled bell-shaped flower.

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.

#303b9a
Original
#004b9d
Protanopia
#004198
Deuteranopia
#005364
Tritanopia
#404040
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).
AAAon White
9.47:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
Failon Black
2.22:1

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
##303B9A
Display P3
Display P3
color(display-p3 0.1967 0.2301 0.5820)
P3 has subtle headroomOKLCH chroma 0.154

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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