#307D9F
Closest named color: Cerulean (#457B9D). oklch(55.7% 0.091 230.7), rgb(48, 125, 159).
Aa
White text reads best on this color (4.60:1).
About this color
#307D9F is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.091 and its hue 231°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.017 away. White text reads best on it, at 4.60:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.091) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.55:1 |
| White text | 4.60:1 |
Values
| HEX | #307D9F |
| RGB | rgb(48, 125, 159) |
| HSL | hsl(198, 54%, 41%) |
| OKLCH | oklch(55.7% 0.091 230.7) |
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 #307D9F | 4.60:1 | AA | Lc -77.2 | Fine for body text |
| Black text on #307D9F | 4.55:1 | AA | Lc 32.4 | Non-text elements, placeholder text |
| #307D9F text on white | 4.60:1 | AA | Lc 71.7 | Content text, not long reading |
| #307D9F text on black | 4.55:1 | AA | Lc -30.0 | Dividers and decoration only |
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 600.
-
Step 50
50
#F2F6F8
oklch(97.1% 0.005 228.8)
-
Step 100
100
#E2EBF0
oklch(93.5% 0.012 231.7)
-
Step 200
200
#CBDCE6
oklch(88.5% 0.023 233.4)
-
Step 300
300
#A7C6D6
oklch(80.9% 0.04 230.3)
-
Step 400
400
#76A9C2
oklch(70.8% 0.065 230)
-
Step 500
500
#4F93B3
oklch(63.1% 0.084 230.5)
-
Step 600
600 (this color)
#307D9F
oklch(55.7% 0.091 230.7)
-
Step 700
700
#216988
oklch(49.1% 0.085 230.9)
-
Step 800
800
#1E566E
oklch(42.8% 0.07 230)
-
Step 900
900
#1F4759
oklch(37.7% 0.054 229.9)
-
Step 950
950
#132A34
oklch(27.1% 0.034 228.3)
#307D9F 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) | #6C7BA1 | 0.063 |
| Deuteranopia (no green cones) | #5D709F | 0.055 |
| Tritanopia (no blue cones) | #008688 | 0.055 |
| Achromatopsia (no color) | #757575 | 0.091 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #307D9F
#307D9F
oklch(55.7% 0.091 230.7)
- #9E6340
#9E6340
oklch(55.7% 0.091 50.7)
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 #307D9F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.017
- Stormy Blue #507B9C ΔE 0.028
- Dull Blue #49759C ΔE 0.028
- Ocean #017B92 ΔE 0.030
- Nice Blue #107AB0 ΔE 0.033
- Teal Blue #01889F ΔE 0.034
- Muted Blue #3B719F ΔE 0.035
- Flat Blue #3C73A8 ΔE 0.036
Use #307D9F 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.