#1666D7
Closest named color: Royal Blue (#4169E1). oklch(53.3% 0.189 258.8), rgb(22, 102, 215).
Aa
White text reads best on this color (5.36:1).
About this color
#1666D7 is a medium-dark, vivid blue. In OKLCH its lightness is 53%, its chroma 0.189 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.037 away. White text reads best on it, at 5.36:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | vivid (0.189) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 3.91:1 |
| White text | 5.36:1 |
Values
| HEX | #1666D7 |
| RGB | rgb(22, 102, 215) |
| HSL | hsl(215, 81%, 46%) |
| OKLCH | oklch(53.3% 0.189 258.8) |
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 #1666D7 | 5.36:1 | AA | Lc -81.4 | Fine for body text |
| Black text on #1666D7 | 3.91:1 | AA large text | Lc 28.1 | Dividers and decoration only |
| #1666D7 text on white | 5.36:1 | AA | Lc 76.0 | Fine for body text |
| #1666D7 text on black | 3.91:1 | AA large text | Lc -25.7 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C7DBF9
oklch(88.6% 0.047 258.4)
-
Step 300
300
#A0C2F8
oklch(80.9% 0.085 259.5)
-
Step 400
400
#6BA1F4
oklch(70.7% 0.135 258.7)
-
Step 500
500
#4187F0
oklch(63.2% 0.173 258.5)
-
Step 600
600 (this color)
#1666D7
oklch(53.3% 0.189 258.8)
-
Step 700
700
#115BC2
oklch(49.2% 0.176 258.8)
-
Step 800
800
#124B9D
oklch(42.8% 0.146 258.7)
-
Step 900
900
#173F7C
oklch(37.6% 0.113 258.9)
-
Step 950
950
#0F2649
oklch(27.2% 0.071 258.7)
#1666D7 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) | #0673DB | 0.033 |
| Deuteranopia (no green cones) | #0063D5 | 0.011 |
| Tritanopia (no blue cones) | #008295 | 0.143 |
| Achromatopsia (no color) | #6B6B6B | 0.189 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1666D7
#1666D7
oklch(53.3% 0.189 258.8)
- #8F6300
#8F6300
oklch(53.2% 0.111 78.3)
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 #1666D7, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.037
- Azul #1D5DEC ΔE 0.039
- Cerulean Blue #056EEE ΔE 0.039
- Neon Blue #4361EE ΔE 0.049
- Warm Blue #4B57DB ΔE 0.051
- Bright Blue #0165FC ΔE 0.056
- Mid Blue #276AB3 ΔE 0.059
- Windows Blue #3778BF ΔE 0.070
Use #1666D7 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.