#3743AB
Closest named color: Sapphire (#2138AB). oklch(43.8% 0.165 272.6), rgb(55, 67, 171).
Aa
White text reads best on this color (8.22:1).
About this color
#3743AB is a dark, vivid blue. In OKLCH its lightness is 44%, its chroma 0.165 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.040 away. White text reads best on it, at 8.22:1.
| Hue family | Blues |
| Lightness | dark (44%) |
| Chroma | vivid (0.165) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.55:1 |
| White text | 8.22:1 |
Values
| HEX | #3743AB |
| RGB | rgb(55, 67, 171) |
| HSL | hsl(234, 51%, 44%) |
| OKLCH | oklch(43.8% 0.165 272.6) |
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 #3743AB | 8.22:1 | AAA | Lc -92.6 | Preferred for body text |
| Black text on #3743AB | 2.55:1 | Fails | Lc 16.1 | Dividers and decoration only |
| #3743AB text on white | 8.22:1 | AAA | Lc 87.9 | Fine for body text |
| #3743AB text on black | 2.55:1 | Fails | Lc -14.2 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E3E9FD
oklch(93.5% 0.028 272.5)
-
Step 200
200
#CDD8FE
oklch(88.6% 0.054 272.5)
-
Step 300
300
#ABBDFF
oklch(80.9% 0.096 272.3)
-
Step 400
400
#8198FF
oklch(70.7% 0.153 272.5)
-
Step 500
500
#647AFE
oklch(63.1% 0.196 272.4)
-
Step 600
600
#4E5EEE
oklch(55.6% 0.215 272.4)
-
Step 700
700
#404CCF
oklch(49.1% 0.2 272.5)
-
Step 800
800 (this color)
#3743AB
oklch(43.8% 0.165 272.6)
-
Step 900
900
#2D3784
oklch(37.6% 0.129 273)
-
Step 950
950
#1A214E
oklch(27% 0.083 273)
#3743AB 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) | #0054AE | 0.050 |
| Deuteranopia (no green cones) | #004AA9 | 0.040 |
| Tritanopia (no blue cones) | #005D70 | 0.136 |
| Achromatopsia (no color) | #4F4F4F | 0.166 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3743AB
#3743AB
oklch(43.8% 0.165 272.6)
- #635000
#635000
oklch(43.8% 0.09 93)
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 #3743AB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.040
- Blueberry #464196 ΔE 0.040
- Blue Blue #2242C7 ΔE 0.049
- Majorelle Blue #3F37C9 ΔE 0.053
- Cobalt #1E488F ΔE 0.055
- Dark Slate Blue #483D8B ΔE 0.058
- Blue With A Hint Of Purple #533CC6 ΔE 0.060
- Dusk Blue #26538D ΔE 0.069
Use #3743AB 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.