#373973
Closest named color: Twilight Blue (#0A437A). oklch(37.4% 0.097 279.1), rgb(55, 57, 115).
Aa
White text reads best on this color (10.52:1).
About this color
#373973 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.097 and its hue 279°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.049 away. White text reads best on it, at 10.52:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.097) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.99:1 |
| White text | 10.52:1 |
Values
| HEX | #373973 |
| RGB | rgb(55, 57, 115) |
| HSL | hsl(238, 35%, 33%) |
| OKLCH | oklch(37.4% 0.097 279.1) |
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 #373973 | 10.52:1 | AAA | Lc -98.2 | Preferred for body text |
| Black text on #373973 | 1.99:1 | Fails | Lc 9.7 | Not readable |
| #373973 text on white | 10.52:1 | AAA | Lc 94.3 | Preferred for body text |
| #373973 text on black | 1.99:1 | Fails | Lc -8.3 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E6E9F8
oklch(93.6% 0.02 276.9)
-
Step 200
200
#D3D7F4
oklch(88.5% 0.04 279.3)
-
Step 300
300
#B6BCF0
oklch(80.8% 0.074 279.5)
-
Step 400
400
#9198E8
oklch(70.6% 0.117 279.1)
-
Step 500
500
#787DE1
oklch(63.2% 0.148 279.1)
-
Step 600
600
#6264CF
oklch(55.7% 0.161 279)
-
Step 700
700
#5152B3
oklch(49.1% 0.15 278.9)
-
Step 800
800
#424491
oklch(42.7% 0.124 278.6)
-
Step 900
900 (this color)
#373973
oklch(37.4% 0.097 279.1)
-
Step 950
950
#202244
oklch(26.9% 0.063 278.8)
#373973 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) | #1F4175 | 0.035 |
| Deuteranopia (no green cones) | #1A3D72 | 0.036 |
| Tritanopia (no blue cones) | #204650 | 0.086 |
| Achromatopsia (no color) | #3F3F3F | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373973
#373973
oklch(37.4% 0.097 279.1)
- #4B4100
#4B4100
oklch(37.4% 0.078 99.4)
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 #373973, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.049
- Dark Slate Blue #483D8B ΔE 0.050
- Marine Blue #01386A ΔE 0.058
- Cobalt #1E488F ΔE 0.061
- Prussian Blue #1D3557 ΔE 0.063
- Dark Grey Blue #29465B ΔE 0.066
- Blueberry #464196 ΔE 0.066
- Light Navy #155084 ΔE 0.071
Use #373973 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.