#1666BD
Closest named color: Mid Blue (#276AB3). oklch(51.4% 0.155 254.8), rgb(22, 102, 189).
Aa
White text reads best on this color (5.72:1).
About this color
#1666BD is a medium-dark, vivid blue. In OKLCH its lightness is 51%, its chroma 0.155 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.023 away. White text reads best on it, at 5.72:1.
| Hue family | Blues |
| Lightness | medium-dark (51%) |
| Chroma | vivid (0.155) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.66:1 |
| White text | 5.72:1 |
Values
| HEX | #1666BD |
| RGB | rgb(22, 102, 189) |
| HSL | hsl(211, 79%, 41%) |
| OKLCH | oklch(51.4% 0.155 254.8) |
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 #1666BD | 5.72:1 | AA | Lc -83.3 | Fine for body text |
| Black text on #1666BD | 3.66:1 | AA large text | Lc 26.0 | Dividers and decoration only |
| #1666BD text on white | 5.72:1 | AA | Lc 78.1 | Fine for body text |
| #1666BD text on black | 3.66:1 | AA large text | Lc -23.7 | 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 700.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF9
oklch(93.6% 0.022 254.4)
-
Step 200
200
#C7DBF5
oklch(88.5% 0.042 255)
-
Step 300
300
#A0C4F1
oklch(81% 0.075 254.2)
-
Step 400
400
#6BA3EA
oklch(70.6% 0.12 254.9)
-
Step 500
500
#418AE4
oklch(63.1% 0.154 255.2)
-
Step 600
600
#1B72D2
oklch(55.6% 0.167 255)
-
Step 700
700 (this color)
#1666BD
oklch(51.4% 0.155 254.8)
-
Step 800
800
#0F4E93
oklch(42.7% 0.129 254.9)
-
Step 900
900
#164275
oklch(37.8% 0.099 254.5)
-
Step 950
950
#0E2745
oklch(27.1% 0.064 254.6)
#1666BD 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) | #366EC0 | 0.033 |
| Deuteranopia (no green cones) | #0460BB | 0.019 |
| Tritanopia (no blue cones) | #007B88 | 0.116 |
| Achromatopsia (no color) | #666666 | 0.155 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1666BD
#1666BD
oklch(51.4% 0.155 254.8)
- #8B5C00
#8B5C00
oklch(51.3% 0.108 74.5)
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 #1666BD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.023
- French Blue #436BAD ΔE 0.046
- Windows Blue #3778BF ΔE 0.058
- Flat Blue #3C73A8 ΔE 0.061
- Nice Blue #107AB0 ΔE 0.064
- Peacock Blue #016795 ΔE 0.066
- Royal Blue #4169E1 ΔE 0.066
- Ocean Blue #03719C ΔE 0.067
Use #1666BD 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.