#3F708F
Closest named color: Metallic Blue (#4F738E). oklch(52.4% 0.072 238.1), rgb(63, 112, 143).
Aa
White text reads best on this color (5.34:1).
About this color
#3F708F is a medium-dark, moderately saturated blue. In OKLCH its lightness is 52%, its chroma 0.072 and its hue 238°. Its hue sits on the cool side of the wheel. The nearest named color is Metallic Blue (#4F738E), ΔE 0.021 away. White text reads best on it, at 5.34:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | moderately saturated (0.072) |
| Temperature | cool |
| Nearest name | Metallic Blue (#4F738E) |
| Black text | 3.92:1 |
| White text | 5.34:1 |
Values
| HEX | #3F708F |
| RGB | rgb(63, 112, 143) |
| HSL | hsl(203, 39%, 40%) |
| OKLCH | oklch(52.4% 0.072 238.1) |
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 #3F708F | 5.34:1 | AA | Lc -81.8 | Fine for body text |
| Black text on #3F708F | 3.92:1 | AA large text | Lc 27.6 | Dividers and decoration only |
| #3F708F text on white | 5.34:1 | AA | Lc 76.5 | Fine for body text |
| #3F708F text on black | 3.92:1 | AA large text | Lc -25.2 | 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
#F3F6F8
oklch(97.1% 0.004 236.5)
-
Step 100
100
#E4EBEF
oklch(93.6% 0.009 232.4)
-
Step 200
200
#CFDBE4
oklch(88.5% 0.018 240)
-
Step 300
300
#AEC4D4
oklch(80.9% 0.033 239.5)
-
Step 400
400
#83A6BE
oklch(70.8% 0.052 238.4)
-
Step 500
500
#6290AD
oklch(63.1% 0.066 236.9)
-
Step 600
600 (this color)
#3F708F
oklch(52.4% 0.072 238.1)
-
Step 700
700
#396683
oklch(49.1% 0.068 238.5)
-
Step 800
800
#30536A
oklch(42.6% 0.056 238.8)
-
Step 900
900
#2B4556
oklch(37.7% 0.043 238.1)
-
Step 950
950
#192832
oklch(26.8% 0.028 238.3)
#3F708F 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) | #626F90 | 0.042 |
| Deuteranopia (no green cones) | #57678E | 0.036 |
| Tritanopia (no blue cones) | #03787A | 0.058 |
| Achromatopsia (no color) | #6B6B6B | 0.072 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F708F
#3F708F
oklch(52.4% 0.072 238.1)
- #8A5F3F
#8A5F3F
oklch(52.4% 0.073 57)
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 #3F708F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Metallic Blue #4F738E ΔE 0.021
- Muted Blue #3B719F ΔE 0.025
- Dull Blue #49759C ΔE 0.027
- Sea Blue #047495 ΔE 0.032
- Ocean Blue #03719C ΔE 0.036
- Cerulean #457B9D ΔE 0.037
- Flat Blue #3C73A8 ΔE 0.039
- Denim #3B638C ΔE 0.039
Use #3F708F 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.