#556BCB
Closest named color: Dark Periwinkle (#665FD1). oklch(55.9% 0.15 271.1), rgb(85, 107, 203).
Aa
White text reads best on this color (4.82:1).
About this color
#556BCB is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.150 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.037 away. White text reads best on it, at 4.82:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.150) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.35:1 |
| White text | 4.82:1 |
Values
| HEX | #556BCB |
| RGB | rgb(85, 107, 203) |
| HSL | hsl(229, 53%, 56%) |
| OKLCH | oklch(55.9% 0.15 271.1) |
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 #556BCB | 4.82:1 | AA | Lc -78.7 | Fine for body text |
| Black text on #556BCB | 4.35:1 | AA large text | Lc 30.8 | Non-text elements, placeholder text |
| #556BCB text on white | 4.82:1 | AA | Lc 73.2 | Content text, not long reading |
| #556BCB text on black | 4.35:1 | AA large text | Lc -28.5 | 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
#D0D8F3
oklch(88.5% 0.038 272.5)
-
Step 300
300
#B0BFED
oklch(80.9% 0.067 270.7)
-
Step 400
400
#889DE4
oklch(70.8% 0.107 270.9)
-
Step 500
500
#6B82DC
oklch(63% 0.138 271.2)
-
Step 600
600 (this color)
#556BCB
oklch(55.9% 0.15 271.1)
-
Step 700
700
#4558AF
oklch(49.1% 0.14 271.2)
-
Step 800
800
#39488D
oklch(42.6% 0.115 271.5)
-
Step 900
900
#303D71
oklch(37.6% 0.09 271)
-
Step 950
950
#1C2442
oklch(26.9% 0.057 270.9)
#556BCB 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) | #3D77CF | 0.036 |
| Deuteranopia (no green cones) | #2B6DC9 | 0.040 |
| Tritanopia (no blue cones) | #008191 | 0.134 |
| Achromatopsia (no color) | #727272 | 0.150 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #556BCB
#556BCB
oklch(55.9% 0.15 271.1)
- #8D7100
#8D7100
oklch(56% 0.114 91.5)
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 #556BCB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.037
- Royal Blue #4169E1 ΔE 0.041
- Slate Blue #6A5ACD ΔE 0.048
- Iris #6258C4 ΔE 0.048
- Windows Blue #3778BF ΔE 0.049
- Light Indigo #6D5ACF ΔE 0.051
- French Blue #436BAD ΔE 0.053
- Warm Blue #4B57DB ΔE 0.059
Use #556BCB 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.