#173A40
Closest named color: Midnight Green (#073B4C). oklch(32.5% 0.041 210.2), rgb(23, 58, 64).
Aa
White text reads best on this color (12.23:1).
About this color
#173A40 is a dark, muted teal or cyan. In OKLCH its lightness is 33%, its chroma 0.041 and its hue 210°. Its hue sits on the cool side of the wheel. The nearest named color is Midnight Green (#073B4C), ΔE 0.022 away. White text reads best on it, at 12.23:1.
| Hue family | Teals and cyans |
| Lightness | dark (33%) |
| Chroma | muted (0.041) |
| Temperature | cool |
| Nearest name | Midnight Green (#073B4C) |
| Black text | 1.71:1 |
| White text | 12.23:1 |
Values
| HEX | #173A40 |
| RGB | rgb(23, 58, 64) |
| HSL | hsl(189, 47%, 17%) |
| OKLCH | oklch(32.5% 0.041 210.2) |
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 #173A40 | 12.23:1 | AAA | Lc -101.3 | Preferred for body text |
| Black text on #173A40 | 1.71:1 | Fails | Lc 0.0 | Not readable |
| #173A40 text on white | 12.23:1 | AAA | Lc 97.8 | Preferred for body text |
| #173A40 text on black | 1.71:1 | Fails | Lc 0.0 | Not readable |
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 900.
-
Step 50
50
#F2F6F7
oklch(97% 0.004 214.3)
-
Step 100
100
#E3ECED
oklch(93.7% 0.01 204.9)
-
Step 200
200
#CDDCDF
oklch(88.4% 0.017 211)
-
Step 300
300
#ABC7CC
oklch(81% 0.031 209.6)
-
Step 400
400
#7CAAB2
oklch(70.8% 0.05 209.4)
-
Step 500
500
#59949F
oklch(63% 0.064 210.7)
-
Step 600
600
#3C7E8A
oklch(55.5% 0.069 211)
-
Step 700
700
#2E6B75
oklch(49.2% 0.064 209.7)
-
Step 800
800
#27575F
oklch(42.7% 0.053 209.8)
-
Step 900
900 (this color)
#173A40
oklch(32.5% 0.041 210.2)
-
Step 950
950
#162A2E
oklch(27% 0.027 211.7)
#173A40 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) | #353840 | 0.039 |
| Deuteranopia (no green cones) | #2F3340 | 0.037 |
| Tritanopia (no blue cones) | #003D3C | 0.020 |
| Achromatopsia (no color) | #353535 | 0.042 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173A40
#173A40
oklch(32.5% 0.041 210.2)
- #472C27
#472C27
oklch(32.5% 0.041 31)
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 #173A40, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Midnight Green #073B4C ΔE 0.022
- Dark Blue Grey #1F3B4D ΔE 0.026
- Gunmetal #293241 ΔE 0.034
- Onyx #343A40 ΔE 0.038
- Space Cadet #2B2D42 ΔE 0.050
- Prussian Blue #1D3557 ΔE 0.050
- Charcoal #264653 ΔE 0.051
- Charcoal Grey #3C4142 ΔE 0.057
Use #173A40 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.