#1B233B
Closest named color: Oxford Blue (#1B263B). oklch(26.1% 0.047 269), rgb(27, 35, 59).
Aa
White text reads best on this color (15.55:1).
About this color
#1B233B is a dark, muted blue. In OKLCH its lightness is 26%, its chroma 0.047 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.010 away. White text reads best on it, at 15.55:1.
| Hue family | Blues |
| Lightness | dark (26%) |
| Chroma | muted (0.047) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.35:1 |
| White text | 15.55:1 |
Values
| HEX | #1B233B |
| RGB | rgb(27, 35, 59) |
| HSL | hsl(225, 37%, 17%) |
| OKLCH | oklch(26.1% 0.047 269) |
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 #1B233B | 15.55:1 | AAA | Lc -105.1 | Preferred for body text |
| Black text on #1B233B | 1.35:1 | Fails | Lc 0.0 | Not readable |
| #1B233B text on white | 15.55:1 | AAA | Lc 102.4 | Preferred for body text |
| #1B233B text on black | 1.35:1 | 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
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E5EAF5
oklch(93.6% 0.016 266.3)
-
Step 200
200
#D1D9EE
oklch(88.6% 0.03 269.1)
-
Step 300
300
#B2C0E5
oklch(80.9% 0.055 268.9)
-
Step 400
400
#8A9ED8
oklch(70.6% 0.088 269.4)
-
Step 500
500
#6D86CE
oklch(63.2% 0.113 268.5)
-
Step 600
600
#566EBB
oklch(55.6% 0.123 269.1)
-
Step 700
700
#465CA1
oklch(49.1% 0.114 268.7)
-
Step 800
800
#3A4B83
oklch(42.7% 0.095 269.3)
-
Step 900
900
#323F69
oklch(37.7% 0.074 269.6)
-
Step 950
950 (this color)
#1B233B
oklch(26.1% 0.047 269)
#1B233B 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) | #1A253C | 0.007 |
| Deuteranopia (no green cones) | #17233A | 0.006 |
| Tritanopia (no blue cones) | #0F282C | 0.041 |
| Achromatopsia (no color) | #242424 | 0.047 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B233B
#1B233B
oklch(26.1% 0.047 269)
- #2D2305
#2D2305
oklch(26.1% 0.047 90.3)
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 #1B233B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.010
- Dark #1B2431 ΔE 0.020
- Jet #212529 ΔE 0.038
- Space Cadet #2B2D42 ΔE 0.045
- Rich Black #0D1B2A ΔE 0.047
- Gunmetal #293241 ΔE 0.057
- Prussian Blue #1D3557 ΔE 0.071
- Marine #042E60 ΔE 0.071
Use #1B233B 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.