#166EC4
Closest named color: Mid Blue (#276AB3). oklch(53.7% 0.155 253.1), rgb(22, 110, 196).
Aa
White text reads best on this color (5.17:1).
About this color
#166EC4 is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.155 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.027 away. White text reads best on it, at 5.17:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.155) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 4.06:1 |
| White text | 5.17:1 |
Values
| HEX | #166EC4 |
| RGB | rgb(22, 110, 196) |
| HSL | hsl(210, 80%, 43%) |
| OKLCH | oklch(53.7% 0.155 253.1) |
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 #166EC4 | 5.17:1 | AA | Lc -80.4 | Fine for body text |
| Black text on #166EC4 | 4.06:1 | AA large text | Lc 29.0 | Dividers and decoration only |
| #166EC4 text on white | 5.17:1 | AA | Lc 75.0 | Fine for body text |
| #166EC4 text on black | 4.06:1 | AA large text | Lc -26.7 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF7
oklch(93.6% 0.019 252.9)
-
Step 200
200
#C8DBF3
oklch(88.5% 0.039 254.3)
-
Step 300
300
#A1C4ED
oklch(80.9% 0.069 252.7)
-
Step 400
400
#6DA4E4
oklch(70.7% 0.111 253)
-
Step 500
500
#438CDD
oklch(63.2% 0.143 253)
-
Step 600
600 (this color)
#166EC4
oklch(53.7% 0.155 253.1)
-
Step 700
700
#0F61AF
oklch(49.1% 0.144 253)
-
Step 800
800
#124F8E
oklch(42.6% 0.12 253.5)
-
Step 900
900
#174271
oklch(37.5% 0.093 253.3)
-
Step 950
950
#0F2742
oklch(26.9% 0.059 253.1)
#166EC4 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) | #4175C7 | 0.038 |
| Deuteranopia (no green cones) | #1C66C2 | 0.021 |
| Tritanopia (no blue cones) | #00838F | 0.116 |
| Achromatopsia (no color) | #6D6D6D | 0.155 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #166EC4
#166EC4
oklch(53.7% 0.155 253.1)
- #956100
#956100
oklch(53.6% 0.114 72.8)
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 #166EC4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.027
- Windows Blue #3778BF ΔE 0.039
- French Blue #436BAD ΔE 0.045
- Nice Blue #107AB0 ΔE 0.051
- Flat Blue #3C73A8 ΔE 0.054
- Royal Blue #4169E1 ΔE 0.057
- Muted Blue #3B719F ΔE 0.064
- Cerulean Blue #056EEE ΔE 0.065
Use #166EC4 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.