#2B3773
Closest named color: Twilight Blue (#0A437A). oklch(36.1% 0.104 271.8), rgb(43, 55, 115).
Aa
White text reads best on this color (11.07:1).
About this color
#2B3773 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.104 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.041 away. White text reads best on it, at 11.07:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.104) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.89:1 |
| White text | 11.07:1 |
Values
| HEX | #2B3773 |
| RGB | rgb(43, 55, 115) |
| HSL | hsl(230, 46%, 31%) |
| OKLCH | oklch(36.1% 0.104 271.8) |
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 #2B3773 | 11.07:1 | AAA | Lc -99.2 | Preferred for body text |
| Black text on #2B3773 | 1.89:1 | Fails | Lc 8.5 | Not readable |
| #2B3773 text on white | 11.07:1 | AAA | Lc 95.4 | Preferred for body text |
| #2B3773 text on black | 1.89:1 | 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E4E9F9
oklch(93.5% 0.022 272.1)
-
Step 200
200
#CFD8F7
oklch(88.5% 0.044 272.7)
-
Step 300
300
#AEBEF4
oklch(80.8% 0.079 271.7)
-
Step 400
400
#859BEE
oklch(70.7% 0.124 271.6)
-
Step 500
500
#6980E8
oklch(63.2% 0.158 271.8)
-
Step 600
600
#5266D7
oklch(55.6% 0.174 272)
-
Step 700
700
#4354BA
oklch(49% 0.161 272)
-
Step 800
800
#374697
oklch(42.8% 0.133 271.7)
-
Step 900
900 (this color)
#2B3773
oklch(36.1% 0.104 271.8)
-
Step 950
950
#1B2346
oklch(26.9% 0.066 271.6)
#2B3773 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) | #173F75 | 0.028 |
| Deuteranopia (no green cones) | #093972 | 0.032 |
| Tritanopia (no blue cones) | #00454F | 0.091 |
| Achromatopsia (no color) | #3C3C3C | 0.104 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2B3773
#2B3773
oklch(36.1% 0.104 271.8)
- #4B3B00
#4B3B00
oklch(35.9% 0.073 91.6)
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 #2B3773, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.041
- Marine Blue #01386A ΔE 0.041
- Prussian Blue #1D3557 ΔE 0.053
- Marine #042E60 ΔE 0.061
- Cobalt #1E488F ΔE 0.062
- Dark Slate Blue #483D8B ΔE 0.064
- Dark Grey Blue #29465B ΔE 0.068
- Dark Blue Grey #1F3B4D ΔE 0.073
Use #2B3773 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.