#427F99
Closest named color: Cerulean (#457B9D). oklch(56.6% 0.075 228), rgb(66, 127, 153).
Aa
Black text reads best on this color (4.72:1).
About this color
#427F99 is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 57%, its chroma 0.075 and its hue 228°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.015 away. Black text reads best on it, at 4.72:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.075) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.72:1 |
| White text | 4.44:1 |
Values
| HEX | #427F99 |
| RGB | rgb(66, 127, 153) |
| HSL | hsl(198, 40%, 43%) |
| OKLCH | oklch(56.6% 0.075 228) |
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 #427F99 | 4.44:1 | AA large text | Lc -76.1 | Fine for body text |
| Black text on #427F99 | 4.72:1 | AA | Lc 33.4 | Non-text elements, placeholder text |
| #427F99 text on white | 4.44:1 | AA large text | Lc 70.7 | Content text, not long reading |
| #427F99 text on black | 4.72:1 | AA | Lc -31.0 | 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
#F2F6F8
oklch(97.1% 0.005 228.8)
-
Step 100
100
#E4EBEF
oklch(93.6% 0.009 232.4)
-
Step 200
200
#CDDCE3
oklch(88.5% 0.019 227.3)
-
Step 300
300
#ABC5D2
oklch(80.8% 0.034 229.4)
-
Step 400
400
#7DA8BB
oklch(70.7% 0.054 227)
-
Step 500
500
#5B92AA
oklch(63.1% 0.068 227.6)
-
Step 600
600 (this color)
#427F99
oklch(56.6% 0.075 228)
-
Step 700
700
#306880
oklch(49% 0.07 228.7)
-
Step 800
800
#295568
oklch(42.7% 0.058 228.5)
-
Step 900
900
#264654
oklch(37.6% 0.045 228.1)
-
Step 950
950
#172931
oklch(26.9% 0.028 227.9)
#427F99 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) | #717D9A | 0.054 |
| Deuteranopia (no green cones) | #657499 | 0.048 |
| Tritanopia (no blue cones) | #008687 | 0.052 |
| Achromatopsia (no color) | #787878 | 0.075 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #427F99
#427F99
oklch(56.6% 0.075 228)
- #9B694F
#9B694F
oklch(56.7% 0.075 48.2)
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 #427F99, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.015
- Stormy Blue #507B9C ΔE 0.019
- Dull Blue #49759C ΔE 0.031
- Metallic Blue #4F738E ΔE 0.035
- Teal Blue #01889F ΔE 0.035
- Grey Blue #647D8E ΔE 0.038
- Ocean #017B92 ΔE 0.039
- Off Blue #5684AE ΔE 0.041
Use #427F99 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.