#4666CB
Closest named color: Royal Blue (#4169E1). oklch(54% 0.161 267.6), rgb(70, 102, 203).
Aa
White text reads best on this color (5.21:1).
About this color
#4666CB is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.161 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.034 away. White text reads best on it, at 5.21:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.161) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.02:1 |
| White text | 5.21:1 |
Values
| HEX | #4666CB |
| RGB | rgb(70, 102, 203) |
| HSL | hsl(226, 56%, 54%) |
| OKLCH | oklch(54% 0.161 267.6) |
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 #4666CB | 5.21:1 | AA | Lc -80.9 | Fine for body text |
| Black text on #4666CB | 4.02:1 | AA large text | Lc 28.5 | Dividers and decoration only |
| #4666CB text on white | 5.21:1 | AA | Lc 75.6 | Fine for body text |
| #4666CB text on black | 4.02:1 | AA large text | Lc -26.2 | 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
#F2F5FC
oklch(97% 0.01 267.4)
-
Step 100
100
#E4EAF8
oklch(93.7% 0.02 267.3)
-
Step 200
200
#CDD9F5
oklch(88.5% 0.041 267.1)
-
Step 300
300
#ACC0F0
oklch(80.9% 0.072 267.1)
-
Step 400
400
#819EE9
oklch(70.8% 0.115 267.3)
-
Step 500
500
#6283E2
oklch(63% 0.148 267.6)
-
Step 600
600 (this color)
#4666CB
oklch(54% 0.161 267.6)
-
Step 700
700
#3C58B4
oklch(49% 0.149 267.8)
-
Step 800
800
#314992
oklch(42.7% 0.124 267.3)
-
Step 900
900
#2B3E74
oklch(37.8% 0.095 267.2)
-
Step 950
950
#192444
oklch(26.9% 0.062 267.8)
#4666CB 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) | #2E73CF | 0.036 |
| Deuteranopia (no green cones) | #0267C9 | 0.042 |
| Tritanopia (no blue cones) | #007E8F | 0.134 |
| Achromatopsia (no color) | #6C6C6C | 0.161 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4666CB
#4666CB
oklch(54% 0.161 267.6)
- #8A6A00
#8A6A00
oklch(54.1% 0.111 87.7)
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 #4666CB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.034
- Dark Periwinkle #665FD1 ΔE 0.044
- Warm Blue #4B57DB ΔE 0.045
- Iris #6258C4 ΔE 0.047
- Mid Blue #276AB3 ΔE 0.050
- French Blue #436BAD ΔE 0.051
- Slate Blue #6A5ACD ΔE 0.053
- Windows Blue #3778BF ΔE 0.055
Use #4666CB 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.