#373988
Closest named color: Dark Slate Blue (#483D8B). oklch(39% 0.129 277.5), rgb(55, 57, 136).
Aa
White text reads best on this color (9.98:1).
About this color
#373988 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.129 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.031 away. White text reads best on it, at 9.98:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.129) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.10:1 |
| White text | 9.98:1 |
Values
| HEX | #373988 |
| RGB | rgb(55, 57, 136) |
| HSL | hsl(239, 42%, 37%) |
| OKLCH | oklch(39% 0.129 277.5) |
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 #373988 | 9.98:1 | AAA | Lc -97.0 | Preferred for body text |
| Black text on #373988 | 2.10:1 | Fails | Lc 11.1 | Not readable |
| #373988 text on white | 9.98:1 | AAA | Lc 92.9 | Preferred for body text |
| #373988 text on black | 2.10:1 | Fails | Lc -9.6 | 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
#F3F5FE
oklch(97.1% 0.012 276.1)
-
Step 100
100
#E5E9FD
oklch(93.7% 0.027 276.8)
-
Step 200
200
#D0D7FD
oklch(88.6% 0.053 277)
-
Step 300
300
#B1BBFF
oklch(80.9% 0.097 277.5)
-
Step 400
400
#8A95FF
oklch(70.7% 0.154 277.2)
-
Step 500
500
#7176FD
oklch(63.2% 0.197 277.6)
-
Step 600
600
#5C59ED
oklch(55.6% 0.216 277.6)
-
Step 700
700
#4C48CE
oklch(49.1% 0.2 277.4)
-
Step 800
800
#3E3CA6
oklch(42.6% 0.165 277.6)
-
Step 900
900 (this color)
#373988
oklch(39% 0.129 277.5)
-
Step 950
950
#1E204D
oklch(27% 0.081 277.5)
#373988 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) | #00468B | 0.052 |
| Deuteranopia (no green cones) | #003F86 | 0.049 |
| Tritanopia (no blue cones) | #034C5A | 0.114 |
| Achromatopsia (no color) | #424242 | 0.130 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373988
#373988
oklch(39% 0.129 277.5)
- #514500
#514500
oklch(39.1% 0.081 97.9)
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 #373988, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.031
- Blueberry #464196 ΔE 0.040
- Cobalt #1E488F ΔE 0.045
- Twilight Blue #0A437A ΔE 0.055
- Sapphire #2138AB ΔE 0.063
- Light Navy #155084 ΔE 0.069
- Dusk Blue #26538D ΔE 0.071
- Marine Blue #01386A ΔE 0.076
Use #373988 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.