#51A1FF
Closest named color: Cornflower Blue (#6495ED). oklch(70.2% 0.159 254.1), rgb(81, 161, 255).
Aa
Black text reads best on this color (7.89:1).
About this color
#51A1FF is a medium-light, vivid blue. In OKLCH its lightness is 70%, its chroma 0.159 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Cornflower Blue (#6495ED), ΔE 0.038 away. Black text reads best on it, at 7.89:1.
| Hue family | Blues |
| Lightness | medium-light (70%) |
| Chroma | vivid (0.159) |
| Temperature | cool |
| Nearest name | Cornflower Blue (#6495ED) |
| Black text | 7.89:1 |
| White text | 2.66:1 |
Values
| HEX | #51A1FF |
| RGB | rgb(81, 161, 255) |
| HSL | hsl(212, 100%, 66%) |
| OKLCH | oklch(70.2% 0.159 254.1) |
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 #51A1FF | 2.66:1 | Fails | Lc -56.6 | Large or bold text, headings |
| Black text on #51A1FF | 7.89:1 | AAA | Lc 52.6 | Large or bold text, headings |
| #51A1FF text on white | 2.66:1 | Fails | Lc 51.4 | Large or bold text, headings |
| #51A1FF text on black | 7.89:1 | AAA | Lc -50.4 | 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
#EFF6FF
oklch(97% 0.014 254.6)
-
Step 100
100
#DDEBFD
oklch(93.5% 0.029 254.7)
-
Step 200
200
#C1DCFE
oklch(88.6% 0.055 254.3)
-
Step 300
300
#94C4FF
oklch(80.8% 0.098 254)
-
Step 400
400 (this color)
#51A1FF
oklch(70.2% 0.159 254.1)
-
Step 500
500
#0088FE
oklch(63.1% 0.201 253.9)
-
Step 600
600
#0072D7
oklch(55.6% 0.177 254)
-
Step 700
700
#005FB6
oklch(49% 0.157 254.2)
-
Step 800
800
#004E97
oklch(42.8% 0.136 254.1)
-
Step 900
900
#00417F
oklch(37.8% 0.12 253.9)
-
Step 950
950
#01264E
oklch(27% 0.084 254)
#51A1FF 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) | #76A7FF | 0.041 |
| Deuteranopia (no green cones) | #5D97FD | 0.026 |
| Tritanopia (no blue cones) | #00B7C4 | 0.124 |
| Achromatopsia (no color) | #9F9F9F | 0.159 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51A1FF
#51A1FF
oklch(70.2% 0.159 254.1)
- #D58E00
#D58E00
oklch(70.1% 0.149 73.7)
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 #51A1FF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cornflower Blue #6495ED ΔE 0.038
- Chefchaouen Blue #4895EF ΔE 0.039
- Dodger Blue #1E90FF ΔE 0.059
- Dark Sky Blue #448EE4 ΔE 0.062
- Periwinkle Blue #8F99FB ΔE 0.066
- Soft Blue #6488EA ΔE 0.066
- Deep Sky Blue #00BFFF ΔE 0.081
- Lavender Blue #8B88F8 ΔE 0.082
Use #51A1FF 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.