#166DAD
Closest named color: Mid Blue (#276AB3). oklch(51.9% 0.127 246.9), rgb(22, 109, 173).
Aa
White text reads best on this color (5.49:1).
About this color
#166DAD is a medium-dark, moderately saturated blue. In OKLCH its lightness is 52%, its chroma 0.127 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.016 away. White text reads best on it, at 5.49:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.82:1 |
| White text | 5.49:1 |
Values
| HEX | #166DAD |
| RGB | rgb(22, 109, 173) |
| HSL | hsl(205, 77%, 38%) |
| OKLCH | oklch(51.9% 0.127 246.9) |
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 #166DAD | 5.49:1 | AA | Lc -82.2 | Fine for body text |
| Black text on #166DAD | 3.82:1 | AA large text | Lc 27.1 | Dividers and decoration only |
| #166DAD text on white | 5.49:1 | AA | Lc 76.9 | Fine for body text |
| #166DAD text on black | 3.82:1 | AA large text | Lc -24.8 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF5
oklch(93.5% 0.017 248)
-
Step 200
200
#C8DCEF
oklch(88.5% 0.034 246.8)
-
Step 300
300
#A1C5E7
oklch(80.9% 0.062 247.1)
-
Step 400
400
#6CA6DB
oklch(70.6% 0.099 247.2)
-
Step 500
500
#418FD1
oklch(63.1% 0.126 247)
-
Step 600
600
#1878BE
oklch(55.6% 0.136 246.9)
-
Step 700
700 (this color)
#166DAD
oklch(51.9% 0.127 246.9)
-
Step 800
800
#0D5285
oklch(42.7% 0.106 247.2)
-
Step 900
900
#16446A
oklch(37.6% 0.082 247.3)
-
Step 950
950
#0F283E
oklch(26.9% 0.052 247.6)
#166DAD 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) | #4E70B0 | 0.047 |
| Deuteranopia (no green cones) | #3863AC | 0.032 |
| Tritanopia (no blue cones) | #007D85 | 0.090 |
| Achromatopsia (no color) | #696969 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #166DAD
#166DAD
oklch(51.9% 0.127 246.9)
- #945900
#945900
oklch(51.9% 0.115 66.6)
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 #166DAD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.016
- French Blue #436BAD ΔE 0.032
- Ocean Blue #03719C ΔE 0.033
- Flat Blue #3C73A8 ΔE 0.034
- Muted Blue #3B719F ΔE 0.037
- Nice Blue #107AB0 ΔE 0.037
- Peacock Blue #016795 ΔE 0.041
- Windows Blue #3778BF ΔE 0.047
Use #166DAD 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.