#42818C
Closest named color: Cerulean (#457B9D). oklch(56.6% 0.067 210.2), rgb(66, 129, 140).
Aa
Black text reads best on this color (4.75:1).
About this color
#42818C is a medium-dark, muted teal or cyan. In OKLCH its lightness is 57%, its chroma 0.067 and its hue 210°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.037 away. Black text reads best on it, at 4.75:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (57%) |
| Chroma | muted (0.067) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.75:1 |
| White text | 4.42:1 |
Values
| HEX | #42818C |
| RGB | rgb(66, 129, 140) |
| HSL | hsl(189, 36%, 40%) |
| OKLCH | oklch(56.6% 0.067 210.2) |
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 #42818C | 4.42:1 | AA large text | Lc -76.0 | Fine for body text |
| Black text on #42818C | 4.75:1 | AA | Lc 33.6 | Non-text elements, placeholder text |
| #42818C text on white | 4.42:1 | AA large text | Lc 70.5 | Content text, not long reading |
| #42818C text on black | 4.75:1 | AA | Lc -31.2 | 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
#F2F6F7
oklch(97% 0.004 214.3)
-
Step 100
100
#E4EBED
oklch(93.5% 0.008 216.6)
-
Step 200
200
#CDDCDF
oklch(88.4% 0.017 211)
-
Step 300
300
#ABC6CB
oklch(80.8% 0.03 210.1)
-
Step 400
400
#7EA9B1
oklch(70.6% 0.048 210.3)
-
Step 500
500
#5B949E
oklch(63.1% 0.062 209.8)
-
Step 600
600 (this color)
#42818C
oklch(56.6% 0.067 210.2)
-
Step 700
700
#306A74
oklch(49% 0.062 210.3)
-
Step 800
800
#29575F
oklch(42.8% 0.052 210.2)
-
Step 900
900
#26474D
oklch(37.5% 0.04 210.5)
-
Step 950
950
#172A2D
oklch(27% 0.025 208.4)
#42818C 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) | #777D8D | 0.063 |
| Deuteranopia (no green cones) | #6C748C | 0.059 |
| Tritanopia (no blue cones) | #0F8684 | 0.036 |
| Achromatopsia (no color) | #787878 | 0.067 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42818C
#42818C
oklch(56.6% 0.067 210.2)
- #9A675F
#9A675F
oklch(56.6% 0.068 29.2)
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 #42818C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.037
- Teal Blue #01889F ΔE 0.037
- Stormy Blue #507B9C ΔE 0.038
- Grey Blue #647D8E ΔE 0.039
- Dark Cyan #008B8B ΔE 0.040
- Teal #008080 ΔE 0.040
- Ocean #017B92 ΔE 0.042
- Metallic Blue #4F738E ΔE 0.044
Use #42818C 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.