#166DF8
Closest named color: Cerulean Blue (#056EEE). oklch(57.3% 0.222 260.4), rgb(22, 109, 248).
Aa
White text reads best on this color (4.58:1).
About this color
#166DF8 is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.222 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.016 away. White text reads best on it, at 4.58:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.222) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.57:1 |
| White text | 4.58:1 |
Values
| HEX | #166DF8 |
| RGB | rgb(22, 109, 248) |
| HSL | hsl(217, 94%, 53%) |
| OKLCH | oklch(57.3% 0.222 260.4) |
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 #166DF8 | 4.58:1 | AA | Lc -76.5 | Fine for body text |
| Black text on #166DF8 | 4.57:1 | AA | Lc 33.1 | Non-text elements, placeholder text |
| #166DF8 text on white | 4.58:1 | AA | Lc 71.0 | Content text, not long reading |
| #166DF8 text on black | 4.57:1 | AA | Lc -30.6 | Non-text elements, placeholder text |
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
#F0F6FF
oklch(97.1% 0.014 258.3)
-
Step 100
100
#DFEBFE
oklch(93.7% 0.029 259.6)
-
Step 200
200
#C4DAFF
oklch(88.4% 0.057 260.8)
-
Step 300
300
#9DC2FF
oklch(81% 0.096 260.2)
-
Step 400
400
#679FFF
oklch(70.7% 0.153 260.6)
-
Step 500
500
#3A83FF
oklch(63.1% 0.199 260.3)
-
Step 600
600 (this color)
#166DF8
oklch(57.3% 0.222 260.4)
-
Step 700
700
#0055D1
oklch(49.1% 0.204 260.3)
-
Step 800
800
#0646AA
oklch(42.6% 0.171 260.4)
-
Step 900
900
#103D87
oklch(37.8% 0.133 260.2)
-
Step 950
950
#0B244F
oklch(27% 0.085 260.5)
#166DF8 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) | #0080FD | 0.046 |
| Deuteranopia (no green cones) | #006CF5 | 0.008 |
| Tritanopia (no blue cones) | #0090A8 | 0.168 |
| Achromatopsia (no color) | #757575 | 0.223 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #166DF8
#166DF8
oklch(57.3% 0.222 260.4)
- #9C6F00
#9C6F00
oklch(57.3% 0.118 80.4)
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 #166DF8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.016
- Bright Blue #0165FC ΔE 0.021
- Clear Blue #247AFD ΔE 0.034
- Neon Blue #4361EE ΔE 0.038
- Azul #1D5DEC ΔE 0.041
- Royal Blue #4169E1 ΔE 0.042
- Electric Blue #0652FF ΔE 0.061
- Warm Blue #4B57DB ΔE 0.071
Use #166DF8 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.