#5566C3
Closest named color: Dark Periwinkle (#665FD1). oklch(54.4% 0.145 272.9), rgb(85, 102, 195).
Aa
White text reads best on this color (5.15:1).
About this color
#5566C3 is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.145 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.036 away. White text reads best on it, at 5.15:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.07:1 |
| White text | 5.15:1 |
Values
| HEX | #5566C3 |
| RGB | rgb(85, 102, 195) |
| HSL | hsl(231, 48%, 55%) |
| OKLCH | oklch(54.4% 0.145 272.9) |
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 #5566C3 | 5.15:1 | AA | Lc -80.7 | Fine for body text |
| Black text on #5566C3 | 4.07:1 | AA large text | Lc 28.8 | Dividers and decoration only |
| #5566C3 text on white | 5.15:1 | AA | Lc 75.3 | Fine for body text |
| #5566C3 text on black | 4.07:1 | AA large text | Lc -26.4 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E5E9F7
oklch(93.5% 0.019 273.2)
-
Step 200
200
#D1D8F2
oklch(88.5% 0.037 273.7)
-
Step 300
300
#B2BFEC
oklch(81% 0.065 272.3)
-
Step 400
400
#8B9CE2
oklch(70.7% 0.105 273)
-
Step 500
500
#6F82DA
oklch(63.1% 0.134 272.8)
-
Step 600
600 (this color)
#5566C3
oklch(54.4% 0.145 272.9)
-
Step 700
700
#4958AC
oklch(49.2% 0.134 272.9)
-
Step 800
800
#3C488B
oklch(42.7% 0.111 273.2)
-
Step 900
900
#333D6F
oklch(37.7% 0.086 273.1)
-
Step 950
950
#1E2441
oklch(27% 0.055 273.4)
#5566C3 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) | #3A72C6 | 0.039 |
| Deuteranopia (no green cones) | #2A69C1 | 0.043 |
| Tritanopia (no blue cones) | #137B8B | 0.129 |
| Achromatopsia (no color) | #6D6D6D | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #5566C3
#5566C3
oklch(54.4% 0.145 272.9)
- #866D00
#866D00
oklch(54.3% 0.111 92.9)
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 #5566C3, closest first.
No curated palette has a color within ΔE 0.04 of #5566C3.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.036
- Iris #6258C4 ΔE 0.037
- Slate Blue #6A5ACD ΔE 0.043
- French Blue #436BAD ΔE 0.045
- Light Indigo #6D5ACF ΔE 0.048
- Royal Blue #4169E1 ΔE 0.050
- Mid Blue #276AB3 ΔE 0.054
- Windows Blue #3778BF ΔE 0.055
Use #5566C3 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.