#373397
Closest named color: Sapphire (#2138AB). oklch(39.2% 0.158 278), rgb(55, 51, 151).
Aa
White text reads best on this color (10.08:1).
About this color
#373397 is a dark, vivid blue. In OKLCH its lightness is 39%, its chroma 0.158 and its hue 278°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.043 away. White text reads best on it, at 10.08:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | vivid (0.158) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.08:1 |
| White text | 10.08:1 |
Values
| HEX | #373397 |
| RGB | rgb(55, 51, 151) |
| HSL | hsl(242, 50%, 40%) |
| OKLCH | oklch(39.2% 0.158 278) |
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 #373397 | 10.08:1 | AAA | Lc -97.0 | Preferred for body text |
| Black text on #373397 | 2.08:1 | Fails | Lc 11.1 | Not readable |
| #373397 text on white | 10.08:1 | AAA | Lc 92.9 | Preferred for body text |
| #373397 text on black | 2.08:1 | 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
#F3F5FF
oklch(97.2% 0.013 277.1)
-
Step 100
100
#E4E8FF
oklch(93.5% 0.031 277.9)
-
Step 200
200
#D0D6FF
oklch(88.5% 0.057 278.6)
-
Step 300
300
#B2BBFF
oklch(81% 0.097 278.2)
-
Step 400
400
#8B94FF
oklch(70.6% 0.155 278)
-
Step 500
500
#7275FF
oklch(63.2% 0.2 278.1)
-
Step 600
600
#5C4FFF
oklch(55.6% 0.249 277.8)
-
Step 700
700
#4D38E6
oklch(49.1% 0.245 277.8)
-
Step 800
800
#3F31B9
oklch(42.7% 0.202 278.2)
-
Step 900
900 (this color)
#373397
oklch(39.2% 0.158 278)
-
Step 950
950
#1E1D56
oklch(27.2% 0.1 278.2)
#373397 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) | #00469A | 0.058 |
| Deuteranopia (no green cones) | #003E95 | 0.051 |
| Tritanopia (no blue cones) | #004D60 | 0.133 |
| Achromatopsia (no color) | #424242 | 0.159 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373397
#373397
oklch(39.2% 0.158 278)
- #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 #373397, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.043
- Blueberry #464196 ΔE 0.044
- Dark Slate Blue #483D8B ΔE 0.045
- Indigo Blue #3A18B1 ΔE 0.057
- Cobalt #1E488F ΔE 0.058
- Imperial Purple #480CA8 ΔE 0.062
- Twilight Blue #0A437A ΔE 0.076
- Chrysanthemum #560BAD ΔE 0.078
Use #373397 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.