#1D3588
Closest named color: Twilight Blue (#0A437A). oklch(36.6% 0.142 266.8), rgb(29, 53, 136).
Aa
White text reads best on this color (10.95:1).
About this color
#1D3588 is a dark, vivid blue. In OKLCH its lightness is 37%, its chroma 0.142 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.047 away. White text reads best on it, at 10.95:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | vivid (0.142) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.91:1 |
| White text | 10.95:1 |
Values
| HEX | #1D3588 |
| RGB | rgb(29, 53, 136) |
| HSL | hsl(227, 65%, 32%) |
| OKLCH | oklch(36.6% 0.142 266.8) |
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 #1D3588 | 10.95:1 | AAA | Lc -98.7 | Preferred for body text |
| Black text on #1D3588 | 1.91:1 | Fails | Lc 9.1 | Not readable |
| #1D3588 text on white | 10.95:1 | AAA | Lc 94.8 | Preferred for body text |
| #1D3588 text on black | 1.91:1 | Fails | Lc -7.8 | 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
#E1EAFF
oklch(93.7% 0.03 267.2)
-
Step 200
200
#C8D9FF
oklch(88.5% 0.056 266.2)
-
Step 300
300
#A5BFFF
oklch(80.9% 0.095 267.2)
-
Step 400
400
#759BFF
oklch(70.6% 0.153 266.8)
-
Step 500
500
#537EFF
oklch(63.1% 0.197 266.8)
-
Step 600
600
#365EFA
oklch(55.5% 0.236 266.9)
-
Step 700
700
#294CDA
oklch(49% 0.219 266.7)
-
Step 800
800
#2240B0
oklch(42.7% 0.181 266.6)
-
Step 900
900 (this color)
#1D3588
oklch(36.6% 0.142 266.8)
-
Step 950
950
#122252
oklch(27.1% 0.09 266.4)
#1D3588 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) | #00428B | 0.035 |
| Deuteranopia (no green cones) | #003886 | 0.019 |
| Tritanopia (no blue cones) | #004A59 | 0.111 |
| Achromatopsia (no color) | #3C3C3C | 0.142 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1D3588
#1D3588
oklch(36.6% 0.142 266.8)
- #503B00
#503B00
oklch(36.6% 0.075 86)
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 #1D3588, closest first.
No curated palette has a color within ΔE 0.04 of #1D3588.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.047
- Cobalt #1E488F ΔE 0.052
- Marine Blue #01386A ΔE 0.057
- Sapphire #2138AB ΔE 0.059
- Royal #0C1793 ΔE 0.067
- Dark Slate Blue #483D8B ΔE 0.068
- Blueberry #464196 ΔE 0.072
- Marine #042E60 ΔE 0.076
Use #1D3588 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.