#51A3FF
Closest named color: Cornflower Blue (#6495ED). oklch(70.6% 0.157 253.2), rgb(81, 163, 255).
Aa
Black text reads best on this color (8.03:1).
About this color
#51A3FF is a medium-light, vivid blue. In OKLCH its lightness is 71%, its chroma 0.157 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Cornflower Blue (#6495ED), ΔE 0.041 away. Black text reads best on it, at 8.03:1.
| Hue family | Blues |
| Lightness | medium-light (71%) |
| Chroma | vivid (0.157) |
| Temperature | cool |
| Nearest name | Cornflower Blue (#6495ED) |
| Black text | 8.03:1 |
| White text | 2.61:1 |
Values
| HEX | #51A3FF |
| RGB | rgb(81, 163, 255) |
| HSL | hsl(212, 100%, 66%) |
| OKLCH | oklch(70.6% 0.157 253.2) |
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 #51A3FF | 2.61:1 | Fails | Lc -55.8 | Large or bold text, headings |
| Black text on #51A3FF | 8.03:1 | AAA | Lc 53.3 | Large or bold text, headings |
| #51A3FF text on white | 2.61:1 | Fails | Lc 50.7 | Large or bold text, headings |
| #51A3FF text on black | 8.03:1 | AAA | Lc -51.2 | Large or bold text, headings |
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 400.
-
Step 50
50
#EFF6FE
oklch(97% 0.013 251.6)
-
Step 100
100
#DDEBFD
oklch(93.5% 0.029 254.7)
-
Step 200
200
#C0DCFD
oklch(88.5% 0.055 252.7)
-
Step 300
300
#93C5FF
oklch(81% 0.098 252.7)
-
Step 400
400 (this color)
#51A3FF
oklch(70.6% 0.157 253.2)
-
Step 500
500
#0089FB
oklch(63.1% 0.196 253.2)
-
Step 600
600
#0073D4
oklch(55.6% 0.172 253.1)
-
Step 700
700
#0060B3
oklch(49% 0.152 253.2)
-
Step 800
800
#004F94
oklch(42.8% 0.131 252.8)
-
Step 900
900
#00417D
oklch(37.6% 0.117 253.3)
-
Step 950
950
#00264D
oklch(26.9% 0.083 253)
#51A3FF 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) | #7AA9FF | 0.044 |
| Deuteranopia (no green cones) | #6099FD | 0.027 |
| Tritanopia (no blue cones) | #00B8C5 | 0.121 |
| Achromatopsia (no color) | #A0A0A0 | 0.157 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51A3FF
#51A3FF
oklch(70.6% 0.157 253.2)
- #D88F00
#D88F00
oklch(70.7% 0.15 73.1)
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 #51A3FF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cornflower Blue #6495ED ΔE 0.041
- Chefchaouen Blue #4895EF ΔE 0.043
- Dodger Blue #1E90FF ΔE 0.063
- Dark Sky Blue #448EE4 ΔE 0.066
- Periwinkle Blue #8F99FB ΔE 0.066
- Soft Blue #6488EA ΔE 0.071
- Deep Sky Blue #00BFFF ΔE 0.076
- Perrywinkle #8F8CE7 ΔE 0.084
Use #51A3FF 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.