#166ECB
Closest named color: Mid Blue (#276AB3). oklch(54.1% 0.164 254.6), rgb(22, 110, 203).
Aa
White text reads best on this color (5.08:1).
About this color
#166ECB is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.164 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.037 away. White text reads best on it, at 5.08:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.164) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 4.12:1 |
| White text | 5.08:1 |
Values
| HEX | #166ECB |
| RGB | rgb(22, 110, 203) |
| HSL | hsl(211, 80%, 44%) |
| OKLCH | oklch(54.1% 0.164 254.6) |
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 #166ECB | 5.08:1 | AA | Lc -79.9 | Fine for body text |
| Black text on #166ECB | 4.12:1 | AA large text | Lc 29.6 | Dividers and decoration only |
| #166ECB text on white | 5.08:1 | AA | Lc 74.5 | Content text, not long reading |
| #166ECB text on black | 4.12:1 | AA large text | Lc -27.2 | 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
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C7DBF4
oklch(88.4% 0.041 254)
-
Step 300
300
#A0C4F0
oklch(81% 0.074 253.7)
-
Step 400
400
#6CA3E9
oklch(70.6% 0.119 255)
-
Step 500
500
#418BE2
oklch(63.2% 0.151 254.3)
-
Step 600
600 (this color)
#166ECB
oklch(54.1% 0.164 254.6)
-
Step 700
700
#0C5FB4
oklch(49% 0.153 254.7)
-
Step 800
800
#104E92
oklch(42.6% 0.127 254.8)
-
Step 900
900
#174274
oklch(37.8% 0.098 254.5)
-
Step 950
950
#0F2744
oklch(27% 0.062 254.6)
#166ECB 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) | #3A76CF | 0.034 |
| Deuteranopia (no green cones) | #0367C9 | 0.021 |
| Tritanopia (no blue cones) | #008592 | 0.124 |
| Achromatopsia (no color) | #6E6E6E | 0.164 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #166ECB
#166ECB
oklch(54.1% 0.164 254.6)
- #966300
#966300
oklch(54.1% 0.115 74)
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 #166ECB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.037
- Windows Blue #3778BF ΔE 0.043
- Royal Blue #4169E1 ΔE 0.047
- French Blue #436BAD ΔE 0.053
- Cerulean Blue #056EEE ΔE 0.054
- Nice Blue #107AB0 ΔE 0.059
- Flat Blue #3C73A8 ΔE 0.063
- Azul #1D5DEC ΔE 0.068
Use #166ECB 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.