#1B283F
Closest named color: Oxford Blue (#1B263B). oklch(27.7% 0.046 261.3), rgb(27, 40, 63).
Aa
White text reads best on this color (14.76:1).
About this color
#1B283F is a dark, muted blue. In OKLCH its lightness is 28%, its chroma 0.046 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.009 away. White text reads best on it, at 14.76:1.
| Hue family | Blues |
| Lightness | dark (28%) |
| Chroma | muted (0.046) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.42:1 |
| White text | 14.76:1 |
Values
| HEX | #1B283F |
| RGB | rgb(27, 40, 63) |
| HSL | hsl(218, 40%, 18%) |
| OKLCH | oklch(27.7% 0.046 261.3) |
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 #1B283F | 14.76:1 | AAA | Lc -104.4 | Preferred for body text |
| Black text on #1B283F | 1.42:1 | Fails | Lc 0.0 | Not readable |
| #1B283F text on white | 14.76:1 | AAA | Lc 101.5 | Preferred for body text |
| #1B283F text on black | 1.42:1 | 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 950.
-
Step 50
50
#F3F6FB
oklch(97.2% 0.007 260.7)
-
Step 100
100
#E4EAF5
oklch(93.6% 0.016 262.8)
-
Step 200
200
#CEDAEE
oklch(88.5% 0.03 260.7)
-
Step 300
300
#ADC2E5
oklch(81% 0.055 260.6)
-
Step 400
400
#82A1D8
oklch(70.7% 0.088 261.6)
-
Step 500
500
#6289CD
oklch(63.1% 0.112 261)
-
Step 600
600
#4972BA
oklch(55.6% 0.122 260.9)
-
Step 700
700
#3B5FA1
oklch(49.2% 0.114 261.5)
-
Step 800
800
#314E82
oklch(42.8% 0.093 261.3)
-
Step 900
900
#2B4168
oklch(37.7% 0.073 261.2)
-
Step 950
950 (this color)
#1B283F
oklch(27.7% 0.046 261.3)
#1B283F 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) | #1F2A40 | 0.010 |
| Deuteranopia (no green cones) | #1B263F | 0.007 |
| Tritanopia (no blue cones) | #0B2D30 | 0.042 |
| Achromatopsia (no color) | #282828 | 0.046 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B283F
#1B283F
oklch(27.7% 0.046 261.3)
- #34260A
#34260A
oklch(27.9% 0.047 81.9)
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 #1B283F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.009
- Dark #1B2431 ΔE 0.027
- Space Cadet #2B2D42 ΔE 0.032
- Jet #212529 ΔE 0.040
- Gunmetal #293241 ΔE 0.042
- Prussian Blue #1D3557 ΔE 0.055
- Rich Black #0D1B2A ΔE 0.061
- Marine #042E60 ΔE 0.061
Use #1B283F 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.