#166D9D
Closest named color: Ocean Blue (#03719C). oklch(51% 0.108 239.6), rgb(22, 109, 157).
Aa
White text reads best on this color (5.66:1).
About this color
#166D9D is a medium-dark, moderately saturated blue. In OKLCH its lightness is 51%, its chroma 0.108 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Ocean Blue (#03719C), ΔE 0.013 away. White text reads best on it, at 5.66:1.
| Hue family | Blues |
| Lightness | medium-dark (51%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Ocean Blue (#03719C) |
| Black text | 3.70:1 |
| White text | 5.66:1 |
Values
| HEX | #166D9D |
| RGB | rgb(22, 109, 157) |
| HSL | hsl(201, 75%, 35%) |
| OKLCH | oklch(51% 0.108 239.6) |
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 #166D9D | 5.66:1 | AA | Lc -83.2 | Fine for body text |
| Black text on #166D9D | 3.70:1 | AA large text | Lc 26.2 | Dividers and decoration only |
| #166D9D text on white | 5.66:1 | AA | Lc 77.9 | Fine for body text |
| #166D9D text on black | 3.70:1 | AA large text | Lc -23.9 | Dividers and decoration only |
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 700.
-
Step 50
50
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1EBF3
oklch(93.5% 0.015 241.8)
-
Step 200
200
#C9DCEB
oklch(88.5% 0.029 241.6)
-
Step 300
300
#A3C6DF
oklch(80.9% 0.052 239.4)
-
Step 400
400
#6FA8D0
oklch(70.8% 0.084 240.1)
-
Step 500
500
#4492C3
oklch(63.2% 0.106 239.2)
-
Step 600
600
#1D7BB0
oklch(55.6% 0.116 239.7)
-
Step 700
700 (this color)
#166D9D
oklch(51% 0.108 239.6)
-
Step 800
800
#11547A
oklch(42.6% 0.089 239.8)
-
Step 900
900
#184663
oklch(37.7% 0.07 240.2)
-
Step 950
950
#10293A
oklch(27% 0.044 240.8)
#166D9D 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) | #566E9F | 0.056 |
| Deuteranopia (no green cones) | #44629C | 0.043 |
| Tritanopia (no blue cones) | #00797E | 0.071 |
| Achromatopsia (no color) | #676767 | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #166D9D
#166D9D
oklch(51% 0.108 239.6)
- #925519
#925519
oklch(51% 0.108 59.9)
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 #166D9D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Ocean Blue #03719C ΔE 0.013
- Peacock Blue #016795 ΔE 0.023
- Sea Blue #047495 ΔE 0.027
- Muted Blue #3B719F ΔE 0.029
- Flat Blue #3C73A8 ΔE 0.037
- Denim #3B638C ΔE 0.039
- Mid Blue #276AB3 ΔE 0.040
- Nice Blue #107AB0 ΔE 0.043
Use #166D9D 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.