#2B3388
Closest named color: Cobalt (#1E488F). oklch(37% 0.14 273.3), rgb(43, 51, 136).
Aa
White text reads best on this color (10.87:1).
About this color
#2B3388 is a dark, vivid blue. In OKLCH its lightness is 37%, its chroma 0.140 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.055 away. White text reads best on it, at 10.87:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | vivid (0.140) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 1.93:1 |
| White text | 10.87:1 |
Values
| HEX | #2B3388 |
| RGB | rgb(43, 51, 136) |
| HSL | hsl(235, 52%, 35%) |
| OKLCH | oklch(37% 0.14 273.3) |
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 #2B3388 | 10.87:1 | AAA | Lc -98.7 | Preferred for body text |
| Black text on #2B3388 | 1.93:1 | Fails | Lc 9.2 | Not readable |
| #2B3388 text on white | 10.87:1 | AAA | Lc 94.7 | Preferred for body text |
| #2B3388 text on black | 1.93:1 | Fails | Lc -7.9 | 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
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E3E9FF
oklch(93.6% 0.03 273.6)
-
Step 200
200
#CDD7FF
oklch(88.4% 0.056 274.2)
-
Step 300
300
#ACBDFF
oklch(80.9% 0.095 273)
-
Step 400
400
#8297FF
oklch(70.6% 0.154 273.2)
-
Step 500
500
#6679FF
oklch(63.1% 0.198 273.3)
-
Step 600
600
#4F58F8
oklch(55.5% 0.234 273.4)
-
Step 700
700
#4147D8
oklch(49.1% 0.216 273.3)
-
Step 800
800
#353CAF
oklch(42.8% 0.18 273.3)
-
Step 900
900 (this color)
#2B3388
oklch(37% 0.14 273.3)
-
Step 950
950
#1A2051
oklch(27% 0.089 273.6)
#2B3388 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) | #00418B | 0.044 |
| Deuteranopia (no green cones) | #003986 | 0.036 |
| Tritanopia (no blue cones) | #004858 | 0.115 |
| Achromatopsia (no color) | #3D3D3D | 0.141 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2B3388
#2B3388
oklch(37% 0.14 273.3)
- #4D3E00
#4D3E00
oklch(36.9% 0.076 93.4)
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 #2B3388, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.055
- Twilight Blue #0A437A ΔE 0.055
- Dark Slate Blue #483D8B ΔE 0.055
- Sapphire #2138AB ΔE 0.060
- Blueberry #464196 ΔE 0.062
- Marine Blue #01386A ΔE 0.066
- Royal #0C1793 ΔE 0.073
- Indigo Blue #3A18B1 ΔE 0.079
Use #2B3388 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.