#5666F4
Closest named color: Neon Blue (#4361EE). oklch(58% 0.211 273), rgb(86, 102, 244).
Aa
Black text reads best on this color (4.60:1).
About this color
#5666F4 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.211 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Neon Blue (#4361EE), ΔE 0.028 away. Black text reads best on it, at 4.60:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.211) |
| Temperature | cool |
| Nearest name | Neon Blue (#4361EE) |
| Black text | 4.60:1 |
| White text | 4.56:1 |
Values
| HEX | #5666F4 |
| RGB | rgb(86, 102, 244) |
| HSL | hsl(234, 88%, 65%) |
| OKLCH | oklch(58% 0.211 273) |
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 #5666F4 | 4.56:1 | AA | Lc -76.7 | Fine for body text |
| Black text on #5666F4 | 4.60:1 | AA | Lc 32.9 | Non-text elements, placeholder text |
| #5666F4 text on white | 4.56:1 | AA | Lc 71.2 | Content text, not long reading |
| #5666F4 text on black | 4.60:1 | AA | Lc -30.5 | Non-text elements, placeholder text |
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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E3E9FD
oklch(93.5% 0.028 272.5)
-
Step 200
200
#CDD8FD
oklch(88.6% 0.052 272.2)
-
Step 300
300
#ACBDFF
oklch(80.9% 0.095 273)
-
Step 400
400
#8298FE
oklch(70.7% 0.151 272.8)
-
Step 500
500
#667AFD
oklch(63.2% 0.194 273)
-
Step 600
600 (this color)
#5666F4
oklch(58% 0.211 273)
-
Step 700
700
#424CCD
oklch(49% 0.197 273.2)
-
Step 800
800
#3640A6
oklch(42.8% 0.162 273.1)
-
Step 900
900
#2E3883
oklch(37.8% 0.125 273.1)
-
Step 950
950
#1A214D
oklch(26.9% 0.081 272.9)
#5666F4 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) | #007DF9 | 0.067 |
| Deuteranopia (no green cones) | #006FF1 | 0.055 |
| Tritanopia (no blue cones) | #0089A3 | 0.175 |
| Achromatopsia (no color) | #767676 | 0.211 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #5666F4
#5666F4
oklch(58% 0.211 273)
- #927700
#927700
oklch(57.8% 0.118 93)
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 #5666F4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Neon Blue #4361EE ΔE 0.028
- Royal Blue #4169E1 ΔE 0.038
- Medium Slate Blue #7B68EE ΔE 0.053
- Warm Blue #4B57DB ΔE 0.054
- Cornflower #6A79F7 ΔE 0.055
- Cerulean Blue #056EEE ΔE 0.055
- Clear Blue #247AFD ΔE 0.056
- Dark Periwinkle #665FD1 ΔE 0.058
Use #5666F4 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.