#63B4E9
Closest named color: Deep Sky Blue (#00BFFF). oklch(74% 0.111 239.3), rgb(99, 180, 233).
Aa
Black text reads best on this color (9.23:1).
About this color
#63B4E9 is a medium-light, moderately saturated blue. In OKLCH its lightness is 74%, its chroma 0.111 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.049 away. Black text reads best on it, at 9.23:1.
| Hue family | Blues |
| Lightness | medium-light (74%) |
| Chroma | moderately saturated (0.111) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.23:1 |
| White text | 2.27:1 |
Values
| HEX | #63B4E9 |
| RGB | rgb(99, 180, 233) |
| HSL | hsl(204, 75%, 65%) |
| OKLCH | oklch(74% 0.111 239.3) |
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 #63B4E9 | 2.27:1 | Fails | Lc -49.5 | Large or bold text, headings |
| Black text on #63B4E9 | 9.23:1 | AAA | Lc 59.3 | Large or bold text, headings |
| #63B4E9 text on white | 2.27:1 | Fails | Lc 44.6 | Non-text elements, placeholder text |
| #63B4E9 text on black | 9.23:1 | AAA | Lc -57.5 | 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
#F0F6FB
oklch(97% 0.009 242.8)
-
Step 100
100
#DEECF6
oklch(93.6% 0.02 238.7)
-
Step 200
200
#C3DDF0
oklch(88.4% 0.038 239.6)
-
Step 300
300
#98C7E9
oklch(80.8% 0.069 240.1)
-
Step 400
400 (this color)
#63B4E9
oklch(74% 0.111 239.3)
-
Step 500
500
#0893D5
oklch(63.1% 0.141 239.2)
-
Step 600
600
#007BB4
oklch(55.5% 0.126 239.3)
-
Step 700
700
#006898
oklch(49.2% 0.11 238.7)
-
Step 800
800
#00557E
oklch(42.8% 0.097 239.2)
-
Step 900
900
#00466A
oklch(37.6% 0.086 240.1)
-
Step 950
950
#032A40
oklch(27.2% 0.058 239.3)
#63B4E9 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) | #9CB4EB | 0.061 |
| Deuteranopia (no green cones) | #8AA6E8 | 0.051 |
| Tritanopia (no blue cones) | #00C1C6 | 0.084 |
| Achromatopsia (no color) | #ACACAC | 0.111 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #63B4E9
#63B4E9
oklch(74% 0.111 239.3)
- #DE9960
#DE9960
oklch(73.9% 0.111 59.4)
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 #63B4E9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.049
- Carolina Blue #8AB8FE ΔE 0.053
- Vivid Sky Blue #4CC9F0 ΔE 0.056
- Lightblue #7BC8F6 ΔE 0.062
- Bright Sky Blue #02CCFE ΔE 0.068
- Sky #82CAFC ΔE 0.071
- Light Grey Blue #9DBCD4 ΔE 0.075
- Light Cornflower Blue #98C1D9 ΔE 0.075
Use #63B4E9 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.