#10339B
Closest named color: Sapphire (#2138AB). oklch(37.6% 0.173 264.5), rgb(16, 51, 155).
Aa
White text reads best on this color (10.66:1).
About this color
#10339B is a dark, vivid blue. In OKLCH its lightness is 38%, its chroma 0.173 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.034 away. White text reads best on it, at 10.66:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | vivid (0.173) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 1.96:1 |
| White text | 10.66:1 |
Values
| HEX | #10339B |
| RGB | rgb(16, 51, 155) |
| HSL | hsl(225, 81%, 34%) |
| OKLCH | oklch(37.6% 0.173 264.5) |
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 #10339B | 10.66:1 | AAA | Lc -97.9 | Preferred for body text |
| Black text on #10339B | 1.96:1 | Fails | Lc 10.1 | Not readable |
| #10339B text on white | 10.66:1 | AAA | Lc 93.8 | Preferred for body text |
| #10339B text on black | 1.96:1 | Fails | Lc -8.7 | 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
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#E0EAFF
oklch(93.6% 0.03 265.3)
-
Step 200
200
#C7D9FF
oklch(88.4% 0.056 265.2)
-
Step 300
300
#A2C0FF
oklch(80.9% 0.096 264.7)
-
Step 400
400
#709DFF
oklch(70.7% 0.152 264.2)
-
Step 500
500
#4B80FF
oklch(63.1% 0.197 264.4)
-
Step 600
600
#275FFF
oklch(55.7% 0.244 264.5)
-
Step 700
700
#0E3FF5
oklch(49% 0.269 264.6)
-
Step 800
800
#0D37C5
oklch(42.6% 0.222 264.5)
-
Step 900
900 (this color)
#10339B
oklch(37.6% 0.173 264.5)
-
Step 950
950
#0A205B
oklch(27.1% 0.11 264.5)
#10339B 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) | #00459E | 0.043 |
| Deuteranopia (no green cones) | #003899 | 0.012 |
| Tritanopia (no blue cones) | #004F62 | 0.132 |
| Achromatopsia (no color) | #3E3E3E | 0.174 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #10339B
#10339B
oklch(37.6% 0.173 264.5)
- #543D00
#543D00
oklch(37.5% 0.077 84.5)
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 #10339B, closest first.
No curated palette has a color within ΔE 0.04 of #10339B.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.034
- Royal #0C1793 ΔE 0.057
- Cobalt #1E488F ΔE 0.061
- Cobalt Blue #030AA7 ΔE 0.064
- Ultramarine #2000B1 ΔE 0.065
- Indigo Blue #3A18B1 ΔE 0.066
- Twilight Blue #0A437A ΔE 0.071
- Blueberry #464196 ΔE 0.079
Use #10339B 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.