#51A4EF
Closest named color: Cornflower Blue (#6495ED). oklch(70% 0.137 248.3), rgb(81, 164, 239).
Aa
Black text reads best on this color (7.90:1).
About this color
#51A4EF is a medium-light, moderately saturated blue. In OKLCH its lightness is 70%, its chroma 0.137 and its hue 248°. 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 7.90:1.
| Hue family | Blues |
| Lightness | medium-light (70%) |
| Chroma | moderately saturated (0.137) |
| Temperature | cool |
| Nearest name | Cornflower Blue (#6495ED) |
| Black text | 7.90:1 |
| White text | 2.65:1 |
Values
| HEX | #51A4EF |
| RGB | rgb(81, 164, 239) |
| HSL | hsl(208, 83%, 63%) |
| OKLCH | oklch(70% 0.137 248.3) |
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 #51A4EF | 2.65:1 | Fails | Lc -56.6 | Large or bold text, headings |
| Black text on #51A4EF | 7.90:1 | AAA | Lc 52.6 | Large or bold text, headings |
| #51A4EF text on white | 2.65:1 | Fails | Lc 51.4 | Large or bold text, headings |
| #51A4EF text on black | 7.90:1 | AAA | Lc -50.5 | 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
#F0F6FD
oklch(97.1% 0.011 252.1)
-
Step 100
100
#DEECFA
oklch(93.7% 0.024 248.1)
-
Step 200
200
#C1DDF8
oklch(88.6% 0.048 247.4)
-
Step 300
300
#95C6F6
oklch(80.9% 0.086 248.4)
-
Step 400
400 (this color)
#51A4EF
oklch(70% 0.137 248.3)
-
Step 500
500
#008EEB
oklch(63.2% 0.171 248.3)
-
Step 600
600
#0077C6
oklch(55.6% 0.15 248.2)
-
Step 700
700
#0064A8
oklch(49.2% 0.133 248.3)
-
Step 800
800
#00528B
oklch(42.9% 0.116 248.2)
-
Step 900
900
#004475
oklch(37.8% 0.103 248.3)
-
Step 950
950
#012848
oklch(27.1% 0.073 248.6)
#51A4EF 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) | #83A7F2 | 0.052 |
| Deuteranopia (no green cones) | #6D98EE | 0.038 |
| Tritanopia (no blue cones) | #00B6BF | 0.104 |
| Achromatopsia (no color) | #9F9F9F | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51A4EF
#51A4EF
oklch(70% 0.137 248.3)
- #D58C2D
#D58C2D
oklch(69.9% 0.137 68.2)
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 #51A4EF, 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
- Dark Sky Blue #448EE4 ΔE 0.062
- Deep Sky Blue #00BFFF ΔE 0.072
- Dodger Blue #1E90FF ΔE 0.073
- Soft Blue #6488EA ΔE 0.073
- Periwinkle Blue #8F99FB ΔE 0.073
- Carolina Blue #8AB8FE ΔE 0.084
Use #51A4EF 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.