#63B4DB
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(73.4% 0.097 231), rgb(99, 180, 219).
Aa
Black text reads best on this color (9.08:1).
About this color
#63B4DB is a medium-light, moderately saturated blue. In OKLCH its lightness is 73%, its chroma 0.097 and its hue 231°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.057 away. Black text reads best on it, at 9.08:1.
| Hue family | Blues |
| Lightness | medium-light (73%) |
| Chroma | moderately saturated (0.097) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 9.08:1 |
| White text | 2.31:1 |
Values
| HEX | #63B4DB |
| RGB | rgb(99, 180, 219) |
| HSL | hsl(199, 62%, 62%) |
| OKLCH | oklch(73.4% 0.097 231) |
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 #63B4DB | 2.31:1 | Fails | Lc -50.3 | Large or bold text, headings |
| Black text on #63B4DB | 9.08:1 | AAA | Lc 58.6 | Large or bold text, headings |
| #63B4DB text on white | 2.31:1 | Fails | Lc 45.4 | Large or bold text, headings |
| #63B4DB text on black | 9.08:1 | AAA | Lc -56.7 | 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
#F0F7FA
oklch(97.2% 0.008 225.1)
-
Step 100
100
#DFECF4
oklch(93.6% 0.018 234.5)
-
Step 200
200
#C4DEEC
oklch(88.6% 0.034 231.2)
-
Step 300
300
#99C8E1
oklch(80.8% 0.061 231.7)
-
Step 400
400 (this color)
#63B4DB
oklch(73.4% 0.097 231)
-
Step 500
500
#0F96C7
oklch(63.2% 0.125 231.1)
-
Step 600
600
#007EA9
oklch(55.6% 0.112 231.2)
-
Step 700
700
#006A8E
oklch(49.1% 0.099 230.6)
-
Step 800
800
#005775
oklch(42.8% 0.086 230.3)
-
Step 900
900
#004862
oklch(37.7% 0.076 230.8)
-
Step 950
950
#032B3B
oklch(27.1% 0.051 230.2)
#63B4DB 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) | #A1B2DD | 0.068 |
| Deuteranopia (no green cones) | #90A5DA | 0.059 |
| Tritanopia (no blue cones) | #00BFC1 | 0.071 |
| Achromatopsia (no color) | #AAAAAA | 0.097 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #63B4DB
#63B4DB
oklch(73.4% 0.097 231)
- #DA9770
#DA9770
oklch(73.3% 0.097 50.9)
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 #63B4DB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.057
- Deep Sky Blue #00BFFF ΔE 0.060
- Turquoise Blue #06B1C4 ΔE 0.061
- Greyblue #77A1B5 ΔE 0.065
- Lightblue #7BC8F6 ΔE 0.067
- Bluegrey #85A3B2 ΔE 0.068
- Carolina Blue #8AB8FE ΔE 0.068
- Light Grey Blue #9DBCD4 ΔE 0.069
Use #63B4DB 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.