#173B4D
Closest named color: Dark Blue Grey (#1F3B4D). oklch(33.5% 0.052 233.1), rgb(23, 59, 77).
Aa
White text reads best on this color (11.86:1).
About this color
#173B4D is a dark, muted blue. In OKLCH its lightness is 33%, its chroma 0.052 and its hue 233°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.008 away. White text reads best on it, at 11.86:1.
| Hue family | Blues |
| Lightness | dark (33%) |
| Chroma | muted (0.052) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.76:1 |
| White text | 11.86:1 |
Values
| HEX | #173B4D |
| RGB | rgb(23, 59, 77) |
| HSL | hsl(200, 54%, 20%) |
| OKLCH | oklch(33.5% 0.052 233.1) |
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 #173B4D | 11.86:1 | AAA | Lc -100.7 | Preferred for body text |
| Black text on #173B4D | 1.76:1 | Fails | Lc 0.0 | Not readable |
| #173B4D text on white | 11.86:1 | AAA | Lc 97.0 | Preferred for body text |
| #173B4D text on black | 1.76:1 | 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
#F2F6F8
oklch(97.1% 0.005 228.8)
-
Step 100
100
#E3EBF0
oklch(93.5% 0.011 234.8)
-
Step 200
200
#CCDCE5
oklch(88.5% 0.021 232.2)
-
Step 300
300
#A9C6D6
oklch(81% 0.039 232)
-
Step 400
400
#79A8C1
oklch(70.7% 0.062 232)
-
Step 500
500
#5592B2
oklch(63.1% 0.08 232.9)
-
Step 600
600
#377C9E
oklch(55.7% 0.087 232.8)
-
Step 700
700
#296887
oklch(49.1% 0.081 233.3)
-
Step 800
800
#24556E
oklch(42.7% 0.067 233.6)
-
Step 900
900 (this color)
#173B4D
oklch(33.5% 0.052 233.1)
-
Step 950
950
#152934
oklch(26.9% 0.033 233.9)
#173B4D 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) | #323A4E | 0.034 |
| Deuteranopia (no green cones) | #2B354D | 0.029 |
| Tritanopia (no blue cones) | #004041 | 0.035 |
| Achromatopsia (no color) | #373737 | 0.052 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173B4D
#173B4D
oklch(33.5% 0.052 233.1)
- #4C2F1C
#4C2F1C
oklch(33.6% 0.052 53.3)
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 #173B4D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.008
- Midnight Green #073B4C ΔE 0.011
- Prussian Blue #1D3557 ΔE 0.030
- Gunmetal #293241 ΔE 0.035
- Onyx #343A40 ΔE 0.041
- Charcoal #264653 ΔE 0.042
- Dark Grey Blue #29465B ΔE 0.047
- Space Cadet #2B2D42 ΔE 0.048
Use #173B4D 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.