#1B357E
Closest named color: Twilight Blue (#0A437A). oklch(35.7% 0.128 265.4), rgb(27, 53, 126).
Aa
White text reads best on this color (11.30:1).
About this color
#1B357E is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.128 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.041 away. White text reads best on it, at 11.30:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.85:1 |
| White text | 11.30:1 |
Values
| HEX | #1B357E |
| RGB | rgb(27, 53, 126) |
| HSL | hsl(224, 65%, 30%) |
| OKLCH | oklch(35.7% 0.128 265.4) |
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 #1B357E | 11.30:1 | AAA | Lc -99.4 | Preferred for body text |
| Black text on #1B357E | 1.85:1 | Fails | Lc 8.3 | Not readable |
| #1B357E text on white | 11.30:1 | AAA | Lc 95.6 | Preferred for body text |
| #1B357E text on black | 1.85:1 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E1EAFD
oklch(93.6% 0.028 265.4)
-
Step 200
200
#C8D9FD
oklch(88.4% 0.053 265.3)
-
Step 300
300
#A3C0FF
oklch(80.9% 0.095 265.2)
-
Step 400
400
#729CFF
oklch(70.6% 0.153 265.4)
-
Step 500
500
#4F7FFE
oklch(63% 0.196 265.5)
-
Step 600
600
#3564EE
oklch(55.6% 0.214 265.4)
-
Step 700
700
#2952CF
oklch(49.1% 0.199 265.5)
-
Step 800
800
#2244A7
oklch(42.7% 0.164 265.4)
-
Step 900
900 (this color)
#1B357E
oklch(35.7% 0.128 265.4)
-
Step 950
950
#13234D
oklch(26.9% 0.08 265.6)
#1B357E 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) | #003F81 | 0.029 |
| Deuteranopia (no green cones) | #00367D | 0.018 |
| Tritanopia (no blue cones) | #004754 | 0.100 |
| Achromatopsia (no color) | #3A3A3A | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B357E
#1B357E
oklch(35.7% 0.128 265.4)
- #4D3900
#4D3900
oklch(35.7% 0.073 86.5)
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 #1B357E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.041
- Marine Blue #01386A ΔE 0.041
- Cobalt #1E488F ΔE 0.059
- Marine #042E60 ΔE 0.060
- Prussian Blue #1D3557 ΔE 0.068
- Midnight Blue #191970 ΔE 0.072
- Royal #0C1793 ΔE 0.073
- Dark Slate Blue #483D8B ΔE 0.073
Use #1B357E 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.