#2B378F
Closest named color: Cobalt (#1E488F). oklch(38.4% 0.145 271.8), rgb(43, 55, 143).
Aa
White text reads best on this color (10.26:1).
About this color
#2B378F is a dark, vivid blue. In OKLCH its lightness is 38%, its chroma 0.145 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.044 away. White text reads best on it, at 10.26:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.04:1 |
| White text | 10.26:1 |
Values
| HEX | #2B378F |
| RGB | rgb(43, 55, 143) |
| HSL | hsl(233, 54%, 36%) |
| OKLCH | oklch(38.4% 0.145 271.8) |
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 #2B378F | 10.26:1 | AAA | Lc -97.5 | Preferred for body text |
| Black text on #2B378F | 2.04:1 | Fails | Lc 10.6 | Not readable |
| #2B378F text on white | 10.26:1 | AAA | Lc 93.4 | Preferred for body text |
| #2B378F text on black | 2.04:1 | Fails | Lc -9.1 | 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
#E2E9FF
oklch(93.5% 0.031 271.7)
-
Step 200
200
#CCD8FF
oklch(88.6% 0.055 271.8)
-
Step 300
300
#AABDFF
oklch(80.8% 0.096 271.7)
-
Step 400
400
#8098FF
oklch(70.7% 0.153 272.1)
-
Step 500
500
#627AFF
oklch(63.1% 0.198 271.8)
-
Step 600
600
#4958FD
oklch(55.6% 0.241 271.7)
-
Step 700
700
#3C46DD
oklch(49.2% 0.225 271.8)
-
Step 800
800
#313BB2
oklch(42.7% 0.186 271.9)
-
Step 900
900 (this color)
#2B378F
oklch(38.4% 0.145 271.8)
-
Step 950
950
#182052
oklch(27% 0.091 272)
#2B378F 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) | #004592 | 0.042 |
| Deuteranopia (no green cones) | #003C8D | 0.033 |
| Tritanopia (no blue cones) | #004D5D | 0.118 |
| Achromatopsia (no color) | #414141 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2B378F
#2B378F
oklch(38.4% 0.145 271.8)
- #534100
#534100
oklch(38.4% 0.078 90.9)
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 #2B378F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.044
- Sapphire #2138AB ΔE 0.047
- Dark Slate Blue #483D8B ΔE 0.049
- Blueberry #464196 ΔE 0.051
- Twilight Blue #0A437A ΔE 0.055
- Light Navy #155084 ΔE 0.073
- Indigo Blue #3A18B1 ΔE 0.074
- Marine Blue #01386A ΔE 0.075
Use #2B378F 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.