#1B374E
Closest named color: Dark Blue Grey (#1F3B4D). oklch(32.6% 0.053 245.3), rgb(27, 55, 78).
Aa
White text reads best on this color (12.33:1).
About this color
#1B374E is a dark, muted blue. In OKLCH its lightness is 33%, its chroma 0.053 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.015 away. White text reads best on it, at 12.33:1.
| Hue family | Blues |
| Lightness | dark (33%) |
| Chroma | muted (0.053) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.70:1 |
| White text | 12.33:1 |
Values
| HEX | #1B374E |
| RGB | rgb(27, 55, 78) |
| HSL | hsl(207, 49%, 21%) |
| OKLCH | oklch(32.6% 0.053 245.3) |
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 #1B374E | 12.33:1 | AAA | Lc -101.4 | Preferred for body text |
| Black text on #1B374E | 1.70:1 | Fails | Lc 0.0 | Not readable |
| #1B374E text on white | 12.33:1 | AAA | Lc 98.0 | Preferred for body text |
| #1B374E text on black | 1.70:1 | 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
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E4EBF1
oklch(93.6% 0.011 243.7)
-
Step 200
200
#CEDBE7
oklch(88.5% 0.022 245.9)
-
Step 300
300
#ACC4D9
oklch(80.9% 0.04 244.7)
-
Step 400
400
#7FA5C6
oklch(70.6% 0.064 245.1)
-
Step 500
500
#5E8FB8
oklch(63.2% 0.082 244.8)
-
Step 600
600
#4378A4
oklch(55.5% 0.089 245.4)
-
Step 700
700
#35658D
oklch(49.1% 0.083 245.7)
-
Step 800
800
#2C5372
oklch(42.8% 0.068 244.4)
-
Step 900
900 (this color)
#1B374E
oklch(32.6% 0.053 245.3)
-
Step 950
950
#182836
oklch(27% 0.034 245.9)
#1B374E 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) | #2D374F | 0.024 |
| Deuteranopia (no green cones) | #26324E | 0.020 |
| Tritanopia (no blue cones) | #003D3F | 0.043 |
| Achromatopsia (no color) | #353535 | 0.053 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B374E
#1B374E
oklch(32.6% 0.053 245.3)
- #472E14
#472E14
oklch(32.5% 0.054 65)
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 #1B374E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.015
- Prussian Blue #1D3557 ΔE 0.019
- Midnight Green #073B4C ΔE 0.020
- Gunmetal #293241 ΔE 0.028
- Space Cadet #2B2D42 ΔE 0.037
- Onyx #343A40 ΔE 0.044
- Marine Blue #01386A ΔE 0.051
- Marine #042E60 ΔE 0.052
Use #1B374E 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.