#6599EE
Closest named color: Cornflower Blue (#6495ED). oklch(68.4% 0.138 259.8), rgb(101, 153, 238).
Aa
Black text reads best on this color (7.34:1).
About this color
#6599EE is a medium-light, moderately saturated blue. In OKLCH its lightness is 68%, its chroma 0.138 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Cornflower Blue (#6495ED), ΔE 0.011 away. Black text reads best on it, at 7.34:1.
| Hue family | Blues |
| Lightness | medium-light (68%) |
| Chroma | moderately saturated (0.138) |
| Temperature | cool |
| Nearest name | Cornflower Blue (#6495ED) |
| Black text | 7.34:1 |
| White text | 2.85:1 |
Values
| HEX | #6599EE |
| RGB | rgb(101, 153, 238) |
| HSL | hsl(217, 80%, 66%) |
| OKLCH | oklch(68.4% 0.138 259.8) |
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 #6599EE | 2.85:1 | Fails | Lc -59.8 | Large or bold text, headings |
| Black text on #6599EE | 7.34:1 | AAA | Lc 49.5 | Large or bold text, headings |
| #6599EE text on white | 2.85:1 | Fails | Lc 54.6 | Large or bold text, headings |
| #6599EE text on black | 7.34:1 | AAA | Lc -47.3 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C7DAFA
oklch(88.4% 0.049 260.9)
-
Step 300
300
#A0C2F9
oklch(80.9% 0.087 259.9)
-
Step 400
400 (this color)
#6599EE
oklch(68.4% 0.138 259.8)
-
Step 500
500
#4386F2
oklch(63.2% 0.176 259.6)
-
Step 600
600
#236CE1
oklch(55.6% 0.192 259.9)
-
Step 700
700
#1559C3
oklch(49% 0.179 259.8)
-
Step 800
800
#154A9E
oklch(42.8% 0.148 259.8)
-
Step 900
900
#183F7D
oklch(37.7% 0.114 259.5)
-
Step 950
950
#0F2549
oklch(26.9% 0.073 259.8)
#6599EE 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) | #76A0F1 | 0.028 |
| Deuteranopia (no green cones) | #6493EC | 0.016 |
| Tritanopia (no blue cones) | #00ACB8 | 0.121 |
| Achromatopsia (no color) | #999999 | 0.138 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6599EE
#6599EE
oklch(68.4% 0.138 259.8)
- #C68E12
#C68E12
oklch(68.4% 0.138 79.6)
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 #6599EE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cornflower Blue #6495ED ΔE 0.011
- Chefchaouen Blue #4895EF ΔE 0.030
- Soft Blue #6488EA ΔE 0.045
- Dark Sky Blue #448EE4 ΔE 0.047
- Periwinkle Blue #8F99FB ΔE 0.055
- Perrywinkle #8F8CE7 ΔE 0.057
- Lavender Blue #8B88F8 ΔE 0.063
- Dodger Blue #1E90FF ΔE 0.064
Use #6599EE 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.