#373F9B
Closest named color: Blueberry (#464196). oklch(41.7% 0.148 274.3), rgb(55, 63, 155).
Aa
White text reads best on this color (8.94:1).
About this color
#373F9B is a dark, vivid blue. In OKLCH its lightness is 42%, its chroma 0.148 and its hue 274°. Its hue sits on the cool side of the wheel. The nearest named color is Blueberry (#464196), ΔE 0.025 away. White text reads best on it, at 8.94:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | vivid (0.148) |
| Temperature | cool |
| Nearest name | Blueberry (#464196) |
| Black text | 2.34:1 |
| White text | 8.94:1 |
Values
| HEX | #373F9B |
| RGB | rgb(55, 63, 155) |
| HSL | hsl(235, 48%, 41%) |
| OKLCH | oklch(41.7% 0.148 274.3) |
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 #373F9B | 8.94:1 | AAA | Lc -94.6 | Preferred for body text |
| Black text on #373F9B | 2.34:1 | Fails | Lc 13.8 | Not readable |
| #373F9B text on white | 8.94:1 | AAA | Lc 90.1 | Preferred for body text |
| #373F9B text on black | 2.34:1 | Fails | Lc -12.2 | 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 800.
-
Step 50
50
#F3F5FE
oklch(97.1% 0.012 276.1)
-
Step 100
100
#E4E9FB
oklch(93.6% 0.025 273.5)
-
Step 200
200
#CFD7FA
oklch(88.4% 0.049 275.2)
-
Step 300
300
#AFBDF9
oklch(80.9% 0.086 274.1)
-
Step 400
400
#8798F6
oklch(70.6% 0.139 274.5)
-
Step 500
500
#6B7CF2
oklch(63.1% 0.176 274.1)
-
Step 600
600
#5561E1
oklch(55.5% 0.193 274.2)
-
Step 700
700
#464FC4
oklch(49.1% 0.18 274.3)
-
Step 800
800 (this color)
#373F9B
oklch(41.7% 0.148 274.3)
-
Step 900
900
#31397E
oklch(37.8% 0.116 274.5)
-
Step 950
950
#1C224A
oklch(27% 0.074 274)
#373F9B 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) | #004E9E | 0.050 |
| Deuteranopia (no green cones) | #004599 | 0.044 |
| Tritanopia (no blue cones) | #005566 | 0.124 |
| Achromatopsia (no color) | #494949 | 0.149 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373F9B
#373F9B
oklch(41.7% 0.148 274.3)
- #5C4B00
#5C4B00
oklch(41.8% 0.086 94)
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 #373F9B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blueberry #464196 ΔE 0.025
- Dark Slate Blue #483D8B ΔE 0.036
- Cobalt #1E488F ΔE 0.040
- Sapphire #2138AB ΔE 0.042
- Dusk Blue #26538D ΔE 0.062
- Light Navy #155084 ΔE 0.069
- Twilight #4E518B ΔE 0.070
- Twilight Blue #0A437A ΔE 0.072
Use #373F9B 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.