#166FAC
Closest named color: Mid Blue (#276AB3). oklch(52.4% 0.124 245.3), rgb(22, 111, 172).
Aa
White text reads best on this color (5.37:1).
About this color
#166FAC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 52%, its chroma 0.124 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.021 away. White text reads best on it, at 5.37:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.90:1 |
| White text | 5.37:1 |
Values
| HEX | #166FAC |
| RGB | rgb(22, 111, 172) |
| HSL | hsl(204, 77%, 38%) |
| OKLCH | oklch(52.4% 0.124 245.3) |
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 #166FAC | 5.37:1 | AA | Lc -81.7 | Fine for body text |
| Black text on #166FAC | 3.90:1 | AA large text | Lc 27.7 | Dividers and decoration only |
| #166FAC text on white | 5.37:1 | AA | Lc 76.3 | Fine for body text |
| #166FAC text on black | 3.90:1 | AA large text | Lc -25.4 | 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 600.
-
Step 50
50
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1EBF4
oklch(93.5% 0.016 245.1)
-
Step 200
200
#C9DCED
oklch(88.6% 0.031 245.1)
-
Step 300
300
#A3C5E3
oklch(80.9% 0.056 245.2)
-
Step 400
400
#70A7D5
oklch(70.8% 0.089 244.8)
-
Step 500
500
#4790CA
oklch(63.2% 0.114 245)
-
Step 600
600 (this color)
#166FAC
oklch(52.4% 0.124 245.3)
-
Step 700
700
#15659D
oklch(49% 0.115 245.5)
-
Step 800
800
#16537F
oklch(42.7% 0.095 245)
-
Step 900
900
#1A4566
oklch(37.7% 0.074 244.9)
-
Step 950
950
#11293C
oklch(27.2% 0.047 244.6)
#166FAC 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) | #5272AF | 0.051 |
| Deuteranopia (no green cones) | #3C64AB | 0.036 |
| Tritanopia (no blue cones) | #007E85 | 0.087 |
| Achromatopsia (no color) | #6A6A6A | 0.124 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #166FAC
#166FAC
oklch(52.4% 0.124 245.3)
- #975900
#975900
oklch(52.3% 0.117 65)
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 #166FAC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.021
- Ocean Blue #03719C ΔE 0.029
- Flat Blue #3C73A8 ΔE 0.030
- Nice Blue #107AB0 ΔE 0.031
- Muted Blue #3B719F ΔE 0.032
- French Blue #436BAD ΔE 0.033
- Peacock Blue #016795 ΔE 0.042
- Sea Blue #047495 ΔE 0.044
Use #166FAC 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.