#0166DB
Closest named color: Azul (#1D5DEC). oklch(53.4% 0.196 257.9), rgb(1, 102, 219).
Aa
White text reads best on this color (5.35:1).
About this color
#0166DB is a medium-dark, vivid blue. In OKLCH its lightness is 53%, its chroma 0.196 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Azul (#1D5DEC), ΔE 0.034 away. White text reads best on it, at 5.35:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | vivid (0.196) |
| Temperature | cool |
| Nearest name | Azul (#1D5DEC) |
| Black text | 3.92:1 |
| White text | 5.35:1 |
Values
| HEX | #0166DB |
| RGB | rgb(1, 102, 219) |
| HSL | hsl(212, 99%, 43%) |
| OKLCH | oklch(53.4% 0.196 257.9) |
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 #0166DB | 5.35:1 | AA | Lc -81.1 | Fine for body text |
| Black text on #0166DB | 3.92:1 | AA large text | Lc 28.3 | Dividers and decoration only |
| #0166DB text on white | 5.35:1 | AA | Lc 75.8 | Fine for body text |
| #0166DB text on black | 3.92:1 | AA large text | Lc -26.0 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C5DBFA
oklch(88.5% 0.049 256.9)
-
Step 300
300
#9DC3FA
oklch(81% 0.088 257.6)
-
Step 400
400
#66A1F7
oklch(70.6% 0.141 257.8)
-
Step 500
500
#3A87F4
oklch(63.2% 0.18 257.8)
-
Step 600
600 (this color)
#0166DB
oklch(53.4% 0.196 257.9)
-
Step 700
700
#005AC4
oklch(49% 0.181 258)
-
Step 800
800
#074A9F
oklch(42.6% 0.151 258)
-
Step 900
900
#123F7E
oklch(37.6% 0.117 258)
-
Step 950
950
#0C264A
oklch(27.1% 0.074 257.4)
#0166DB 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) | #0074DF | 0.036 |
| Deuteranopia (no green cones) | #0062D9 | 0.010 |
| Tritanopia (no blue cones) | #008396 | 0.148 |
| Achromatopsia (no color) | #6B6B6B | 0.196 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0166DB
#0166DB
oklch(53.4% 0.196 257.9)
- #906300
#906300
oklch(53.4% 0.111 77.6)
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 #0166DB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Azul #1D5DEC ΔE 0.034
- Cerulean Blue #056EEE ΔE 0.035
- Royal Blue #4169E1 ΔE 0.039
- Neon Blue #4361EE ΔE 0.049
- Bright Blue #0165FC ΔE 0.050
- Warm Blue #4B57DB ΔE 0.054
- Mid Blue #276AB3 ΔE 0.066
- Electric Blue #0652FF ΔE 0.070
Use #0166DB 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.