#1D3C8B
Closest named color: Cobalt (#1E488F). oklch(38.4% 0.137 264.5), rgb(29, 60, 139).
Aa
White text reads best on this color (10.13:1).
About this color
#1D3C8B is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.137 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.033 away. White text reads best on it, at 10.13:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.137) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.07:1 |
| White text | 10.13:1 |
Values
| HEX | #1D3C8B |
| RGB | rgb(29, 60, 139) |
| HSL | hsl(223, 65%, 33%) |
| OKLCH | oklch(38.4% 0.137 264.5) |
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 #1D3C8B | 10.13:1 | AAA | Lc -97.2 | Preferred for body text |
| Black text on #1D3C8B | 2.07:1 | Fails | Lc 10.9 | Not readable |
| #1D3C8B text on white | 10.13:1 | AAA | Lc 93.1 | Preferred for body text |
| #1D3C8B text on black | 2.07:1 | Fails | Lc -9.4 | 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
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#E0EAFE
oklch(93.6% 0.029 264.4)
-
Step 200
200
#C7D9FF
oklch(88.4% 0.056 265.2)
-
Step 300
300
#A2C0FF
oklch(80.9% 0.096 264.7)
-
Step 400
400
#709DFF
oklch(70.7% 0.152 264.2)
-
Step 500
500
#4B80FF
oklch(63.1% 0.197 264.4)
-
Step 600
600
#2C62F6
oklch(55.5% 0.229 264.5)
-
Step 700
700
#2050D6
oklch(49.1% 0.212 264.5)
-
Step 800
800
#1C43AD
oklch(42.8% 0.175 264.5)
-
Step 900
900 (this color)
#1D3C8B
oklch(38.4% 0.137 264.5)
-
Step 950
950
#102350
oklch(27% 0.086 264.2)
#1D3C8B 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) | #00478E | 0.031 |
| Deuteranopia (no green cones) | #003D89 | 0.018 |
| Tritanopia (no blue cones) | #00505D | 0.109 |
| Achromatopsia (no color) | #414141 | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1D3C8B
#1D3C8B
oklch(38.4% 0.137 264.5)
- #573F00
#573F00
oklch(38.4% 0.079 84.1)
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 #1D3C8B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.033
- Twilight Blue #0A437A ΔE 0.038
- Sapphire #2138AB ΔE 0.054
- Dark Slate Blue #483D8B ΔE 0.059
- Light Navy #155084 ΔE 0.059
- Blueberry #464196 ΔE 0.060
- Marine Blue #01386A ΔE 0.062
- Dusk Blue #26538D ΔE 0.067
Use #1D3C8B 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.