#5B66EC
Closest named color: Neon Blue (#4361EE). oklch(57.6% 0.199 274.7), rgb(91, 102, 236).
Aa
White text reads best on this color (4.60:1).
About this color
#5B66EC is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.199 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Neon Blue (#4361EE), ΔE 0.033 away. White text reads best on it, at 4.60:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.199) |
| Temperature | cool |
| Nearest name | Neon Blue (#4361EE) |
| Black text | 4.55:1 |
| White text | 4.60:1 |
Values
| HEX | #5B66EC |
| RGB | rgb(91, 102, 236) |
| HSL | hsl(235, 79%, 64%) |
| OKLCH | oklch(57.6% 0.199 274.7) |
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 #5B66EC | 4.60:1 | AA | Lc -77.1 | Fine for body text |
| Black text on #5B66EC | 4.55:1 | AA | Lc 32.5 | Non-text elements, placeholder text |
| #5B66EC text on white | 4.60:1 | AA | Lc 71.6 | Content text, not long reading |
| #5B66EC text on black | 4.55:1 | AA | Lc -30.1 | 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
#F3F5FE
oklch(97.1% 0.012 276.1)
-
Step 100
100
#E4E9FC
oklch(93.6% 0.026 274.1)
-
Step 200
200
#CFD7FB
oklch(88.5% 0.05 275.4)
-
Step 300
300
#AFBDFB
oklch(81% 0.089 274.4)
-
Step 400
400
#8798F9
oklch(70.8% 0.143 274.7)
-
Step 500
500
#6B7AF6
oklch(63% 0.184 274.7)
-
Step 600
600 (this color)
#5B66EC
oklch(57.6% 0.199 274.7)
-
Step 700
700
#474EC7
oklch(49.2% 0.185 274.8)
-
Step 800
800
#3A41A1
oklch(42.8% 0.153 274.7)
-
Step 900
900
#313880
oklch(37.7% 0.12 274.9)
-
Step 950
950
#1C214B
oklch(26.9% 0.077 274.9)
#5B66EC 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) | #007BF1 | 0.069 |
| Deuteranopia (no green cones) | #006FE9 | 0.062 |
| Tritanopia (no blue cones) | #00869F | 0.169 |
| Achromatopsia (no color) | #757575 | 0.200 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #5B66EC
#5B66EC
oklch(57.6% 0.199 274.7)
- #907700
#907700
oklch(57.6% 0.118 94.2)
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 #5B66EC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Neon Blue #4361EE ΔE 0.033
- Royal Blue #4169E1 ΔE 0.034
- Dark Periwinkle #665FD1 ΔE 0.045
- Medium Slate Blue #7B68EE ΔE 0.047
- Warm Blue #4B57DB ΔE 0.050
- Cornflower #6A79F7 ΔE 0.053
- Light Indigo #6D5ACF ΔE 0.055
- Slate Blue #6A5ACD ΔE 0.056
Use #5B66EC 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.