#066BD7
Closest named color: Cerulean Blue (#056EEE). oklch(54.2% 0.185 256.4), rgb(6, 107, 215).
Aa
White text reads best on this color (5.13:1).
About this color
#066BD7 is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.185 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.036 away. White text reads best on it, at 5.13:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.185) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.09:1 |
| White text | 5.13:1 |
Values
| HEX | #066BD7 |
| RGB | rgb(6, 107, 215) |
| HSL | hsl(211, 95%, 43%) |
| OKLCH | oklch(54.2% 0.185 256.4) |
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 #066BD7 | 5.13:1 | AA | Lc -80.0 | Fine for body text |
| Black text on #066BD7 | 4.09:1 | AA large text | Lc 29.5 | Dividers and decoration only |
| #066BD7 text on white | 5.13:1 | AA | Lc 74.6 | Content text, not long reading |
| #066BD7 text on black | 4.09:1 | AA large text | Lc -27.1 | 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
#E0EBFA
oklch(93.6% 0.024 256.1)
-
Step 200
200
#C6DBF8
oklch(88.5% 0.046 256.5)
-
Step 300
300
#9EC3F6
oklch(80.9% 0.083 256.5)
-
Step 400
400
#67A2F2
oklch(70.6% 0.133 256.4)
-
Step 500
500
#3B88ED
oklch(63% 0.17 256.5)
-
Step 600
600 (this color)
#066BD7
oklch(54.2% 0.185 256.4)
-
Step 700
700
#005DBE
oklch(49.2% 0.17 256.3)
-
Step 800
800
#074C9A
oklch(42.6% 0.142 256.4)
-
Step 900
900
#12407B
oklch(37.6% 0.112 256.7)
-
Step 950
950
#0D2648
oklch(27% 0.07 257)
#066BD7 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) | #2277DB | 0.035 |
| Deuteranopia (no green cones) | #0066D5 | 0.014 |
| Tritanopia (no blue cones) | #008697 | 0.139 |
| Achromatopsia (no color) | #6E6E6E | 0.185 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #066BD7
#066BD7
oklch(54.2% 0.185 256.4)
- #946400
#946400
oklch(54.1% 0.114 76)
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 #066BD7, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.036
- Royal Blue #4169E1 ΔE 0.037
- Azul #1D5DEC ΔE 0.047
- Neon Blue #4361EE ΔE 0.055
- Mid Blue #276AB3 ΔE 0.056
- Bright Blue #0165FC ΔE 0.059
- Warm Blue #4B57DB ΔE 0.061
- Windows Blue #3778BF ΔE 0.061
Use #066BD7 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.