#556FCB
Closest named color: Windows Blue (#3778BF). oklch(56.7% 0.145 269.5), rgb(85, 111, 203).
Aa
White text reads best on this color (4.64:1).
About this color
#556FCB is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.145 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.043 away. White text reads best on it, at 4.64:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.52:1 |
| White text | 4.64:1 |
Values
| HEX | #556FCB |
| RGB | rgb(85, 111, 203) |
| HSL | hsl(227, 53%, 56%) |
| OKLCH | oklch(56.7% 0.145 269.5) |
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 #556FCB | 4.64:1 | AA | Lc -77.5 | Fine for body text |
| Black text on #556FCB | 4.52:1 | AA | Lc 32.0 | Non-text elements, placeholder text |
| #556FCB text on white | 4.64:1 | AA | Lc 72.0 | Content text, not long reading |
| #556FCB text on black | 4.52:1 | AA | Lc -29.6 | 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
#E5EAF7
oklch(93.7% 0.018 269.1)
-
Step 200
200
#CFD9F2
oklch(88.5% 0.036 268.3)
-
Step 300
300
#B0BFEC
oklch(80.9% 0.066 270.5)
-
Step 400
400
#879DE2
oklch(70.6% 0.104 270.1)
-
Step 500
500
#6984DA
oklch(63.1% 0.133 269.2)
-
Step 600
600 (this color)
#556FCB
oklch(56.7% 0.145 269.5)
-
Step 700
700
#4359AC
oklch(49% 0.135 269.7)
-
Step 800
800
#37498B
oklch(42.6% 0.111 269.7)
-
Step 900
900
#2F3E6F
oklch(37.7% 0.086 269.2)
-
Step 950
950
#1C2541
oklch(27.1% 0.054 269.1)
#556FCB 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) | #457ACE | 0.031 |
| Deuteranopia (no green cones) | #3470C9 | 0.033 |
| Tritanopia (no blue cones) | #008493 | 0.129 |
| Achromatopsia (no color) | #747474 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #556FCB
#556FCB
oklch(56.7% 0.145 269.5)
- #917200
#917200
oklch(56.6% 0.116 89.7)
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 #556FCB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.043
- Royal Blue #4169E1 ΔE 0.045
- Dark Periwinkle #665FD1 ΔE 0.045
- French Blue #436BAD ΔE 0.053
- Slate Blue #6A5ACD ΔE 0.056
- Iris #6258C4 ΔE 0.058
- Light Indigo #6D5ACF ΔE 0.059
- Mid Blue #276AB3 ΔE 0.062
Use #556FCB 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.