#1B3755
Closest named color: Prussian Blue (#1D3557). oklch(33.1% 0.063 251.7), rgb(27, 55, 85).
Aa
White text reads best on this color (12.17:1).
About this color
#1B3755 is a dark, muted blue. In OKLCH its lightness is 33%, its chroma 0.063 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.008 away. White text reads best on it, at 12.17:1.
| Hue family | Blues |
| Lightness | dark (33%) |
| Chroma | muted (0.063) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.72:1 |
| White text | 12.17:1 |
Values
| HEX | #1B3755 |
| RGB | rgb(27, 55, 85) |
| HSL | hsl(211, 52%, 22%) |
| OKLCH | oklch(33.1% 0.063 251.7) |
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 #1B3755 | 12.17:1 | AAA | Lc -101.2 | Preferred for body text |
| Black text on #1B3755 | 1.72:1 | Fails | Lc 0.0 | Not readable |
| #1B3755 text on white | 12.17:1 | AAA | Lc 97.6 | Preferred for body text |
| #1B3755 text on black | 1.72:1 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E3EBF3
oklch(93.6% 0.014 248)
-
Step 200
200
#CDDBEB
oklch(88.6% 0.027 251.7)
-
Step 300
300
#ABC3DF
oklch(80.8% 0.048 252.4)
-
Step 400
400
#7EA4CF
oklch(70.7% 0.076 252)
-
Step 500
500
#5C8DC3
oklch(63.1% 0.098 251.8)
-
Step 600
600
#4176AF
oklch(55.5% 0.106 251.8)
-
Step 700
700
#336397
oklch(49.1% 0.099 252.1)
-
Step 800
800
#2B517A
oklch(42.7% 0.081 251.8)
-
Step 900
900 (this color)
#1B3755
oklch(33.1% 0.063 251.7)
-
Step 950
950
#17283A
oklch(27.1% 0.041 250.8)
#1B3755 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) | #2A3956 | 0.021 |
| Deuteranopia (no green cones) | #223354 | 0.014 |
| Tritanopia (no blue cones) | #003E42 | 0.051 |
| Achromatopsia (no color) | #353535 | 0.063 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B3755
#1B3755
oklch(33.1% 0.063 251.7)
- #492F09
#492F09
oklch(32.9% 0.063 71.7)
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 #1B3755, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.008
- Dark Blue Grey #1F3B4D ΔE 0.023
- Midnight Green #073B4C ΔE 0.028
- Gunmetal #293241 ΔE 0.038
- Marine Blue #01386A ΔE 0.039
- Space Cadet #2B2D42 ΔE 0.043
- Marine #042E60 ΔE 0.043
- Onyx #343A40 ΔE 0.052
Use #1B3755 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.