#31739B
Closest named color: Muted Blue (#3B719F). oklch(53.1% 0.092 238.5), rgb(49, 115, 155).
Aa
White text reads best on this color (5.17:1).
About this color
#31739B is a medium-dark, moderately saturated blue. In OKLCH its lightness is 53%, its chroma 0.092 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Muted Blue (#3B719F), ΔE 0.013 away. White text reads best on it, at 5.17:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | moderately saturated (0.092) |
| Temperature | cool |
| Nearest name | Muted Blue (#3B719F) |
| Black text | 4.05:1 |
| White text | 5.17:1 |
Values
| HEX | #31739B |
| RGB | rgb(49, 115, 155) |
| HSL | hsl(203, 52%, 40%) |
| OKLCH | oklch(53.1% 0.092 238.5) |
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 #31739B | 5.17:1 | AA | Lc -80.8 | Fine for body text |
| Black text on #31739B | 4.05:1 | AA large text | Lc 28.7 | Dividers and decoration only |
| #31739B text on white | 5.17:1 | AA | Lc 75.4 | Fine for body text |
| #31739B text on black | 4.05:1 | AA large text | Lc -26.3 | 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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E3EBF1
oklch(93.6% 0.012 239.9)
-
Step 200
200
#CCDCE7
oklch(88.6% 0.023 237.7)
-
Step 300
300
#A9C5D9
oklch(80.9% 0.041 239.1)
-
Step 400
400
#7AA7C5
oklch(70.7% 0.065 238.1)
-
Step 500
500
#5691B7
oklch(63.2% 0.084 238.3)
-
Step 600
600 (this color)
#31739B
oklch(53.1% 0.092 238.5)
-
Step 700
700
#2B678B
oklch(49.1% 0.084 238.3)
-
Step 800
800
#255471
oklch(42.7% 0.07 238.6)
-
Step 900
900
#23465C
oklch(37.8% 0.055 238.2)
-
Step 950
950
#152936
oklch(27% 0.036 238.5)
#31739B 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) | #60739D | 0.050 |
| Deuteranopia (no green cones) | #52689A | 0.043 |
| Tritanopia (no blue cones) | #007D81 | 0.062 |
| Achromatopsia (no color) | #6D6D6D | 0.092 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #31739B
#31739B
oklch(53.1% 0.092 238.5)
- #935E32
#935E32
oklch(53.1% 0.091 58.6)
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 #31739B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Muted Blue #3B719F ΔE 0.013
- Ocean Blue #03719C ΔE 0.023
- Sea Blue #047495 ΔE 0.024
- Flat Blue #3C73A8 ΔE 0.024
- Dull Blue #49759C ΔE 0.024
- Cerulean #457B9D ΔE 0.032
- Metallic Blue #4F738E ΔE 0.034
- Nice Blue #107AB0 ΔE 0.035
Use #31739B 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.