#309CB9
Closest named color: Cadet Blue (#5F9EA0). oklch(64.5% 0.103 219.9), rgb(48, 156, 185).
Aa
Black text reads best on this color (6.58:1).
About this color
#309CB9 is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 65%, its chroma 0.103 and its hue 220°. Its hue sits on the cool side of the wheel. The nearest named color is Cadet Blue (#5F9EA0), ΔE 0.051 away. Black text reads best on it, at 6.58:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (65%) |
| Chroma | moderately saturated (0.103) |
| Temperature | cool |
| Nearest name | Cadet Blue (#5F9EA0) |
| Black text | 6.58:1 |
| White text | 3.19:1 |
Values
| HEX | #309CB9 |
| RGB | rgb(48, 156, 185) |
| HSL | hsl(193, 59%, 46%) |
| OKLCH | oklch(64.5% 0.103 219.9) |
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 #309CB9 | 3.19:1 | AA large text | Lc -64.1 | Content text, not long reading |
| Black text on #309CB9 | 6.58:1 | AA | Lc 45.3 | Large or bold text, headings |
| #309CB9 text on white | 3.19:1 | AA large text | Lc 58.7 | Large or bold text, headings |
| #309CB9 text on black | 6.58:1 | AA | Lc -43.0 | Non-text elements, placeholder text |
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 500.
-
Step 50
50
#F1F7F9
oklch(97.2% 0.007 219.6)
-
Step 100
100
#E0ECF1
oklch(93.6% 0.015 224.5)
-
Step 200
200
#C6DEE6
oklch(88.5% 0.028 219.8)
-
Step 300
300
#9DC9D7
oklch(80.9% 0.05 219.3)
-
Step 400
400
#63ADC3
oklch(70.8% 0.08 219.2)
-
Step 500
500 (this color)
#309CB9
oklch(64.5% 0.103 219.9)
-
Step 600
600
#00809C
oklch(55.5% 0.101 220.3)
-
Step 700
700
#006C84
oklch(49.2% 0.09 220.2)
-
Step 800
800
#00586C
oklch(42.6% 0.078 220.2)
-
Step 900
900
#03495A
oklch(37.6% 0.067 220.5)
-
Step 950
950
#082B35
oklch(27% 0.043 220.9)
#309CB9 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) | #8A98BB | 0.086 |
| Deuteranopia (no green cones) | #788AB9 | 0.078 |
| Tritanopia (no blue cones) | #00A5A5 | 0.048 |
| Achromatopsia (no color) | #909090 | 0.104 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #309CB9
#309CB9
oklch(64.5% 0.103 219.9)
- #C3775D
#C3775D
oklch(64.5% 0.103 39.6)
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 #309CB9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cadet Blue #5F9EA0 ΔE 0.051
- Blue NCS #118AB2 ΔE 0.056
- Sea #3C9992 ΔE 0.057
- Turquoise Blue #06B1C4 ΔE 0.058
- Teal Green #0A9396 ΔE 0.059
- Faded Blue #658CBB ΔE 0.059
- Dusty Blue #5A86AD ΔE 0.064
- Greyblue #77A1B5 ΔE 0.065
Use #309CB9 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.