#1B4273
Closest named color: Twilight Blue (#0A437A). oklch(37.8% 0.095 255.6), rgb(27, 66, 115).
Aa
White text reads best on this color (10.12:1).
About this color
#1B4273 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.095 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.015 away. White text reads best on it, at 10.12:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.095) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.07:1 |
| White text | 10.12:1 |
Values
| HEX | #1B4273 |
| RGB | rgb(27, 66, 115) |
| HSL | hsl(213, 62%, 28%) |
| OKLCH | oklch(37.8% 0.095 255.6) |
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 #1B4273 | 10.12:1 | AAA | Lc -97.3 | Preferred for body text |
| Black text on #1B4273 | 2.07:1 | Fails | Lc 10.7 | Not readable |
| #1B4273 text on white | 10.12:1 | AAA | Lc 93.2 | Preferred for body text |
| #1B4273 text on black | 2.07:1 | Fails | Lc -9.3 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C8DBF4
oklch(88.5% 0.04 255.3)
-
Step 300
300
#A2C3EF
oklch(80.8% 0.072 255.7)
-
Step 400
400
#6FA3E7
oklch(70.7% 0.115 255.5)
-
Step 500
500
#488ADF
oklch(63% 0.145 255.7)
-
Step 600
600
#2772CD
oklch(55.5% 0.158 255.7)
-
Step 700
700
#195FB1
oklch(49% 0.147 255.6)
-
Step 800
800
#184E90
oklch(42.7% 0.122 255.8)
-
Step 900
900 (this color)
#1B4273
oklch(37.8% 0.095 255.6)
-
Step 950
950
#112743
oklch(27.1% 0.059 255.4)
#1B4273 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) | #2B4675 | 0.022 |
| Deuteranopia (no green cones) | #1C3E72 | 0.012 |
| Tritanopia (no blue cones) | #004D55 | 0.072 |
| Achromatopsia (no color) | #424242 | 0.095 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B4273
#1B4273
oklch(37.8% 0.095 255.6)
- #5A3B00
#5A3B00
oklch(37.9% 0.08 75.8)
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 #1B4273, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.015
- Marine Blue #01386A ΔE 0.040
- Light Navy #155084 ΔE 0.046
- Dark Grey Blue #29465B ΔE 0.048
- Cobalt #1E488F ΔE 0.049
- Deep Sea Blue #015482 ΔE 0.055
- Prussian Blue #1D3557 ΔE 0.058
- Charcoal #264653 ΔE 0.061
Use #1B4273 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.