#1B355E
Closest named color: Prussian Blue (#1D3557). oklch(33.1% 0.08 259.2), rgb(27, 53, 94).
Aa
White text reads best on this color (12.22:1).
About this color
#1B355E is a dark, moderately saturated blue. In OKLCH its lightness is 33%, its chroma 0.080 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.013 away. White text reads best on it, at 12.22:1.
| Hue family | Blues |
| Lightness | dark (33%) |
| Chroma | moderately saturated (0.080) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.71:1 |
| White text | 12.22:1 |
Values
| HEX | #1B355E |
| RGB | rgb(27, 53, 94) |
| HSL | hsl(217, 55%, 24%) |
| OKLCH | oklch(33.1% 0.08 259.2) |
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 #1B355E | 12.22:1 | AAA | Lc -101.2 | Preferred for body text |
| Black text on #1B355E | 1.71:1 | Fails | Lc 0.0 | Not readable |
| #1B355E text on white | 12.22:1 | AAA | Lc 97.7 | Preferred for body text |
| #1B355E text on black | 1.71:1 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF6
oklch(93.5% 0.018 261.3)
-
Step 200
200
#CCDAF0
oklch(88.5% 0.034 259.4)
-
Step 300
300
#AAC2E8
oklch(80.9% 0.06 259.5)
-
Step 400
400
#7DA2DC
oklch(70.8% 0.095 259.2)
-
Step 500
500
#5B89D3
oklch(63% 0.123 259.5)
-
Step 600
600
#4172C0
oklch(55.6% 0.133 259.3)
-
Step 700
700
#335FA6
oklch(49.1% 0.124 259.5)
-
Step 800
800
#2A4E86
oklch(42.7% 0.102 259)
-
Step 900
900 (this color)
#1B355E
oklch(33.1% 0.08 259.2)
-
Step 950
950
#17263F
oklch(26.9% 0.051 260.2)
#1B355E 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) | #223960 | 0.016 |
| Deuteranopia (no green cones) | #18325D | 0.010 |
| Tritanopia (no blue cones) | #003E45 | 0.063 |
| Achromatopsia (no color) | #353535 | 0.080 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B355E
#1B355E
oklch(33.1% 0.08 259.2)
- #483100
#483100
oklch(33.2% 0.069 80)
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 #1B355E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.013
- Marine Blue #01386A ΔE 0.026
- Marine #042E60 ΔE 0.032
- Dark Blue Grey #1F3B4D ΔE 0.040
- Midnight Green #073B4C ΔE 0.044
- Gunmetal #293241 ΔE 0.052
- Space Cadet #2B2D42 ΔE 0.053
- Twilight Blue #0A437A ΔE 0.058
Use #1B355E 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.