#1D3787
Closest named color: Twilight Blue (#0A437A). oklch(37% 0.138 266), rgb(29, 55, 135).
Aa
White text reads best on this color (10.77:1).
About this color
#1D3787 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.138 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.042 away. White text reads best on it, at 10.77:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.138) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.94:1 |
| White text | 10.77:1 |
Values
| HEX | #1D3787 |
| RGB | rgb(29, 55, 135) |
| HSL | hsl(225, 65%, 32%) |
| OKLCH | oklch(37% 0.138 266) |
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 #1D3787 | 10.77:1 | AAA | Lc -98.4 | Preferred for body text |
| Black text on #1D3787 | 1.94:1 | Fails | Lc 9.4 | Not readable |
| #1D3787 text on white | 10.77:1 | AAA | Lc 94.5 | Preferred for body text |
| #1D3787 text on black | 1.94:1 | Fails | Lc -8.1 | 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
#F1F5FF
oklch(97% 0.014 268.5)
-
Step 100
100
#E0EAFF
oklch(93.6% 0.03 265.3)
-
Step 200
200
#C8D9FF
oklch(88.5% 0.056 266.2)
-
Step 300
300
#A4C0FF
oklch(81% 0.095 265.8)
-
Step 400
400
#749CFF
oklch(70.8% 0.152 266)
-
Step 500
500
#517FFF
oklch(63.2% 0.197 266)
-
Step 600
600
#3461F7
oklch(55.7% 0.229 266)
-
Step 700
700
#284ED7
oklch(49.1% 0.214 266.2)
-
Step 800
800
#2141AE
oklch(42.7% 0.178 266.1)
-
Step 900
900 (this color)
#1D3787
oklch(37% 0.138 266)
-
Step 950
950
#122250
oklch(26.9% 0.087 266.2)
#1D3787 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) | #00438A | 0.033 |
| Deuteranopia (no green cones) | #003985 | 0.019 |
| Tritanopia (no blue cones) | #004B59 | 0.109 |
| Achromatopsia (no color) | #3E3E3E | 0.138 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1D3787
#1D3787
oklch(37% 0.138 266)
- #513C00
#513C00
oklch(36.9% 0.076 86.3)
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 #1D3787, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.042
- Cobalt #1E488F ΔE 0.048
- Marine Blue #01386A ΔE 0.055
- Sapphire #2138AB ΔE 0.060
- Dark Slate Blue #483D8B ΔE 0.065
- Blueberry #464196 ΔE 0.070
- Light Navy #155084 ΔE 0.071
- Royal #0C1793 ΔE 0.072
Use #1D3787 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.