#427BAB
Closest named color: Cerulean (#457B9D). oklch(56.5% 0.096 246), rgb(66, 123, 171).
Aa
Black text reads best on this color (4.65:1).
About this color
#427BAB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.096 and its hue 246°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.022 away. Black text reads best on it, at 4.65:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.096) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.65:1 |
| White text | 4.51:1 |
Values
| HEX | #427BAB |
| RGB | rgb(66, 123, 171) |
| HSL | hsl(207, 44%, 46%) |
| OKLCH | oklch(56.5% 0.096 246) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #427BAB | 4.51:1 | AA | Lc -76.6 | Fine for body text |
| Black text on #427BAB | 4.65:1 | AA | Lc 32.9 | Non-text elements, placeholder text |
| #427BAB text on white | 4.51:1 | AA | Lc 71.2 | Content text, not long reading |
| #427BAB text on black | 4.65:1 | AA | Lc -30.5 | Non-text elements, placeholder text |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 600.
-
Step 50
50
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E3EBF2
oklch(93.6% 0.013 244.3)
-
Step 200
200
#CDDBE8
oklch(88.5% 0.023 246.1)
-
Step 300
300
#ABC4DB
oklch(80.9% 0.042 246.1)
-
Step 400
400
#7DA5CA
oklch(70.6% 0.07 246.9)
-
Step 500
500
#5B8FBC
oklch(63.2% 0.088 245.9)
-
Step 600
600 (this color)
#427BAB
oklch(56.5% 0.096 246)
-
Step 700
700
#316590
oklch(49.1% 0.089 245.9)
-
Step 800
800
#295275
oklch(42.6% 0.075 246.5)
-
Step 900
900
#26445E
oklch(37.6% 0.058 246.2)
-
Step 950
950
#172837
oklch(26.9% 0.036 246.3)
#427BAB with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #667CAD | 0.041 |
| Deuteranopia (no green cones) | #5872AA | 0.032 |
| Tritanopia (no blue cones) | #00868C | 0.074 |
| Achromatopsia (no color) | #767676 | 0.096 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #427BAB
#427BAB
oklch(56.5% 0.096 246)
- #9C6A33
#9C6A33
oklch(56.6% 0.096 66.2)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #427BAB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.022
- Steel Blue #4682B4 ΔE 0.023
- Flat Blue #3C73A8 ΔE 0.024
- Dull Blue #49759C ΔE 0.025
- Stormy Blue #507B9C ΔE 0.026
- Nice Blue #107AB0 ΔE 0.031
- Cool Blue #4984B8 ΔE 0.031
- Muted Blue #3B719F ΔE 0.033
Use #427BAB in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.