#5666ED
Closest named color: Neon Blue (#4361EE). oklch(57.4% 0.202 273.1), rgb(86, 102, 237).
Aa
White text reads best on this color (4.64:1).
About this color
#5666ED is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.202 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Neon Blue (#4361EE), ΔE 0.027 away. White text reads best on it, at 4.64:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.202) |
| Temperature | cool |
| Nearest name | Neon Blue (#4361EE) |
| Black text | 4.51:1 |
| White text | 4.64:1 |
Values
| HEX | #5666ED |
| RGB | rgb(86, 102, 237) |
| HSL | hsl(234, 81%, 63%) |
| OKLCH | oklch(57.4% 0.202 273.1) |
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 #5666ED | 4.64:1 | AA | Lc -77.3 | Fine for body text |
| Black text on #5666ED | 4.51:1 | AA | Lc 32.2 | Non-text elements, placeholder text |
| #5666ED text on white | 4.64:1 | AA | Lc 71.8 | Content text, not long reading |
| #5666ED text on black | 4.51:1 | AA | Lc -29.8 | 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
#F3F5FE
oklch(97.1% 0.012 276.1)
-
Step 100
100
#E4E9FC
oklch(93.6% 0.026 274.1)
-
Step 200
200
#CED8FB
oklch(88.6% 0.049 272.8)
-
Step 300
300
#ADBDFC
oklch(80.9% 0.091 273.2)
-
Step 400
400
#8498FA
oklch(70.7% 0.145 273.4)
-
Step 500
500
#677BF8
oklch(63.1% 0.186 273.1)
-
Step 600
600 (this color)
#5666ED
oklch(57.4% 0.202 273.1)
-
Step 700
700
#434EC9
oklch(49.1% 0.189 273.3)
-
Step 800
800
#3641A2
oklch(42.6% 0.156 273)
-
Step 900
900
#2E3881
oklch(37.6% 0.123 273.2)
-
Step 950
950
#1B224B
oklch(27% 0.076 273)
#5666ED 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) | #007BF2 | 0.065 |
| Deuteranopia (no green cones) | #006EEA | 0.056 |
| Tritanopia (no blue cones) | #0087A0 | 0.168 |
| Achromatopsia (no color) | #747474 | 0.202 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #5666ED
#5666ED
oklch(57.4% 0.202 273.1)
- #907600
#907600
oklch(57.4% 0.118 93.5)
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 #5666ED, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Neon Blue #4361EE ΔE 0.027
- Royal Blue #4169E1 ΔE 0.030
- Warm Blue #4B57DB ΔE 0.048
- Dark Periwinkle #665FD1 ΔE 0.048
- Medium Slate Blue #7B68EE ΔE 0.053
- Cerulean Blue #056EEE ΔE 0.054
- Cornflower #6A79F7 ΔE 0.057
- Light Indigo #6D5ACF ΔE 0.059
Use #5666ED 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.