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Firm Plectranthus

#3b74cd
Notes

Firm Plectranthus (#3B74CD) is a true azure with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (217°, 59%, 52%) 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
#3b74cd
RGB
rgb(59, 116, 205)
HSL
hsl(217, 59%, 52%)
HWB
hwb(217 23% 20%)
OKLCH
oklch(56.6% 0.150 259.1)
P3
color(display-p3 0.2870 0.4496 0.7793)
HSV
hsv(217, 71%, 80%)
LAB
lab(49.28% 11.28 -51.57)
LCH
lch(49.28% 52.79 282.34)
CMYK
cmyk(71%, 43%, 0%, 20%)

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.

Plectranthus
noun

The genus Plectranthus — particularly P. ecklonii, the South African blue spur flower whose fall-blooming blue flower spikes attract sunbirds. The color refers to a fresh P. ecklonii at peak autumn bloom: a saturated, slightly cool deep blue-violet with the matte finish of small clustered mint-family flowers.

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.

#3b74cd
Original
#487cd0
Protanopia
#2e6fcb
Deuteranopia
#008996
Tritanopia
#6e6e6e
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).
AAon White
4.60:1
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
4.57:1

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
##3B74CD
Display P3
Display P3
color(display-p3 0.2870 0.4496 0.7793)
P3 has subtle headroomOKLCH chroma 0.150

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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