#373B9D
Closest named color: Blueberry (#464196). oklch(41.2% 0.156 275.4), rgb(55, 59, 157).
Aa
White text reads best on this color (9.23:1).
About this color
#373B9D is a dark, vivid blue. In OKLCH its lightness is 41%, its chroma 0.156 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Blueberry (#464196), ΔE 0.031 away. White text reads best on it, at 9.23:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | vivid (0.156) |
| Temperature | cool |
| Nearest name | Blueberry (#464196) |
| Black text | 2.27:1 |
| White text | 9.23:1 |
Values
| HEX | #373B9D |
| RGB | rgb(55, 59, 157) |
| HSL | hsl(238, 48%, 42%) |
| OKLCH | oklch(41.2% 0.156 275.4) |
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 #373B9D | 9.23:1 | AAA | Lc -95.2 | Preferred for body text |
| Black text on #373B9D | 2.27:1 | Fails | Lc 13.1 | Not readable |
| #373B9D text on white | 9.23:1 | AAA | Lc 90.8 | Preferred for body text |
| #373B9D text on black | 2.27:1 | Fails | Lc -11.5 | 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
#E4E9FC
oklch(93.6% 0.026 274.1)
-
Step 200
200
#CFD7FB
oklch(88.5% 0.05 275.4)
-
Step 300
300
#AFBCFC
oklch(80.8% 0.092 275.3)
-
Step 400
400
#8897FA
oklch(70.7% 0.145 275.5)
-
Step 500
500
#6D79F8
oklch(63.1% 0.187 275.6)
-
Step 600
600
#575EE7
oklch(55.6% 0.204 275.4)
-
Step 700
700
#484CC8
oklch(49% 0.189 275.5)
-
Step 800
800 (this color)
#373B9D
oklch(41.2% 0.156 275.4)
-
Step 900
900
#313781
oklch(37.6% 0.123 275.3)
-
Step 950
950
#1D214B
oklch(27% 0.077 275.9)
#373B9D 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) | #004CA0 | 0.053 |
| Deuteranopia (no green cones) | #00439B | 0.045 |
| Tritanopia (no blue cones) | #005366 | 0.129 |
| Achromatopsia (no color) | #474747 | 0.157 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373B9D
#373B9D
oklch(41.2% 0.156 275.4)
- #594A00
#594A00
oklch(41.2% 0.085 95.7)
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 #373B9D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blueberry #464196 ΔE 0.031
- Sapphire #2138AB ΔE 0.036
- Dark Slate Blue #483D8B ΔE 0.041
- Cobalt #1E488F ΔE 0.047
- Indigo Blue #3A18B1 ΔE 0.065
- Majorelle Blue #3F37C9 ΔE 0.071
- Dusk Blue #26538D ΔE 0.072
- Blue Blue #2242C7 ΔE 0.072
Use #373B9D 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.