#5166FB
Closest named color: Neon Blue (#4361EE). oklch(58.2% 0.221 271.5), rgb(81, 102, 251).
Aa
Black text reads best on this color (4.64:1).
About this color
#5166FB is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.221 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Neon Blue (#4361EE), ΔE 0.029 away. Black text reads best on it, at 4.64:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.221) |
| Temperature | cool |
| Nearest name | Neon Blue (#4361EE) |
| Black text | 4.64:1 |
| White text | 4.52:1 |
Values
| HEX | #5166FB |
| RGB | rgb(81, 102, 251) |
| HSL | hsl(233, 96%, 65%) |
| OKLCH | oklch(58.2% 0.221 271.5) |
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 #5166FB | 4.52:1 | AA | Lc -76.3 | Fine for body text |
| Black text on #5166FB | 4.64:1 | AA | Lc 33.2 | Non-text elements, placeholder text |
| #5166FB text on white | 4.52:1 | AA | Lc 70.9 | Content text, not long reading |
| #5166FB text on black | 4.64:1 | AA | Lc -30.8 | 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
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E3E9FE
oklch(93.6% 0.029 273.1)
-
Step 200
200
#CCD8FF
oklch(88.6% 0.055 271.8)
-
Step 300
300
#AABDFF
oklch(80.8% 0.096 271.7)
-
Step 400
400
#7F98FF
oklch(70.6% 0.153 271.7)
-
Step 500
500
#617AFF
oklch(63% 0.198 271.6)
-
Step 600
600 (this color)
#5166FB
oklch(58.2% 0.221 271.5)
-
Step 700
700
#3D4BD2
oklch(49% 0.205 271.7)
-
Step 800
800
#323FAA
oklch(42.7% 0.17 271.7)
-
Step 900
900
#2A3787
oklch(37.7% 0.134 271.4)
-
Step 950
950
#19214F
oklch(27% 0.085 272.1)
#5166FB 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) | #007EFF | 0.064 |
| Deuteranopia (no green cones) | #006FF8 | 0.049 |
| Tritanopia (no blue cones) | #008BA7 | 0.179 |
| Achromatopsia (no color) | #767676 | 0.222 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #5166FB
#5166FB
oklch(58.2% 0.221 271.5)
- #957700
#957700
oklch(58.1% 0.119 91.1)
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 #5166FB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Neon Blue #4361EE ΔE 0.029
- Royal Blue #4169E1 ΔE 0.044
- Bright Blue #0165FC ΔE 0.052
- Clear Blue #247AFD ΔE 0.052
- Cerulean Blue #056EEE ΔE 0.053
- Cornflower #6A79F7 ΔE 0.059
- Azul #1D5DEC ΔE 0.059
- Warm Blue #4B57DB ΔE 0.060
Use #5166FB 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.