#066BD8
Closest named color: Cerulean Blue (#056EEE). oklch(54.2% 0.186 256.5), rgb(6, 107, 216).
Aa
White text reads best on this color (5.11:1).
About this color
#066BD8 is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.186 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.034 away. White text reads best on it, at 5.11:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.186) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.10:1 |
| White text | 5.11:1 |
Values
| HEX | #066BD8 |
| RGB | rgb(6, 107, 216) |
| HSL | hsl(211, 95%, 44%) |
| OKLCH | oklch(54.2% 0.186 256.5) |
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 #066BD8 | 5.11:1 | AA | Lc -79.9 | Fine for body text |
| Black text on #066BD8 | 4.10:1 | AA large text | Lc 29.6 | Dividers and decoration only |
| #066BD8 text on white | 5.11:1 | AA | Lc 74.5 | Content text, not long reading |
| #066BD8 text on black | 4.10:1 | 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
#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
#9EC3F7
oklch(80.9% 0.084 256.9)
-
Step 400
400
#67A2F3
oklch(70.7% 0.135 256.6)
-
Step 500
500
#3B88EE
oklch(63% 0.171 256.7)
-
Step 600
600 (this color)
#066BD8
oklch(54.2% 0.186 256.5)
-
Step 700
700
#005DBF
oklch(49.2% 0.171 256.5)
-
Step 800
800
#074C9B
oklch(42.7% 0.143 256.6)
-
Step 900
900
#12407B
oklch(37.6% 0.112 256.7)
-
Step 950
950
#0C2648
oklch(26.9% 0.071 256.4)
#066BD8 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) | #2077DC | 0.035 |
| Deuteranopia (no green cones) | #0066D6 | 0.014 |
| Tritanopia (no blue cones) | #008697 | 0.140 |
| Achromatopsia (no color) | #6E6E6E | 0.186 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #066BD8
#066BD8
oklch(54.2% 0.186 256.5)
- #946500
#946500
oklch(54.3% 0.114 76.9)
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 #066BD8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.034
- Royal Blue #4169E1 ΔE 0.037
- Azul #1D5DEC ΔE 0.046
- Neon Blue #4361EE ΔE 0.053
- Bright Blue #0165FC ΔE 0.057
- Mid Blue #276AB3 ΔE 0.058
- Warm Blue #4B57DB ΔE 0.060
- Windows Blue #3778BF ΔE 0.062
Use #066BD8 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.