#3739A0
Closest named color: Sapphire (#2138AB). oklch(41.1% 0.163 275.7), rgb(55, 57, 160).
Aa
White text reads best on this color (9.31:1).
About this color
#3739A0 is a dark, vivid blue. In OKLCH its lightness is 41%, its chroma 0.163 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.032 away. White text reads best on it, at 9.31:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | vivid (0.163) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.25:1 |
| White text | 9.31:1 |
Values
| HEX | #3739A0 |
| RGB | rgb(55, 57, 160) |
| HSL | hsl(239, 49%, 42%) |
| OKLCH | oklch(41.1% 0.163 275.7) |
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 #3739A0 | 9.31:1 | AAA | Lc -95.3 | Preferred for body text |
| Black text on #3739A0 | 2.25:1 | Fails | Lc 13.0 | Not readable |
| #3739A0 text on white | 9.31:1 | AAA | Lc 91.0 | Preferred for body text |
| #3739A0 text on black | 2.25:1 | Fails | Lc -11.4 | 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
#E4E9FD
oklch(93.6% 0.028 274.7)
-
Step 200
200
#CFD7FD
oklch(88.5% 0.053 275.9)
-
Step 300
300
#AFBCFE
oklch(80.9% 0.095 275.5)
-
Step 400
400
#8796FE
oklch(70.7% 0.152 275.6)
-
Step 500
500
#6C78FC
oklch(63.1% 0.194 275.4)
-
Step 600
600
#575CEB
oklch(55.6% 0.211 275.6)
-
Step 700
700
#484ACD
oklch(49.1% 0.197 275.7)
-
Step 800
800 (this color)
#3739A0
oklch(41.1% 0.163 275.7)
-
Step 900
900
#313683
oklch(37.6% 0.127 275.6)
-
Step 950
950
#1D214D
oklch(27.1% 0.08 275.8)
#3739A0 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) | #004CA3 | 0.056 |
| Deuteranopia (no green cones) | #00429E | 0.046 |
| Tritanopia (no blue cones) | #005367 | 0.134 |
| Achromatopsia (no color) | #474747 | 0.163 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3739A0
#3739A0
oklch(41.1% 0.163 275.7)
- #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 #3739A0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.032
- Blueberry #464196 ΔE 0.036
- Dark Slate Blue #483D8B ΔE 0.046
- Cobalt #1E488F ΔE 0.053
- Indigo Blue #3A18B1 ΔE 0.058
- Majorelle Blue #3F37C9 ΔE 0.067
- Blue Blue #2242C7 ΔE 0.068
- Imperial Purple #480CA8 ΔE 0.069
Use #3739A0 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.