#3F799E
Closest named color: Cerulean (#457B9D). oklch(55.3% 0.084 238.8), rgb(63, 121, 158).
Aa
White text reads best on this color (4.72:1).
About this color
#3F799E is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.084 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.009 away. White text reads best on it, at 4.72:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.084) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.44:1 |
| White text | 4.72:1 |
Values
| HEX | #3F799E |
| RGB | rgb(63, 121, 158) |
| HSL | hsl(203, 43%, 43%) |
| OKLCH | oklch(55.3% 0.084 238.8) |
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 #3F799E | 4.72:1 | AA | Lc -78.1 | Fine for body text |
| Black text on #3F799E | 4.44:1 | AA large text | Lc 31.4 | Non-text elements, placeholder text |
| #3F799E text on white | 4.72:1 | AA | Lc 72.7 | Content text, not long reading |
| #3F799E text on black | 4.44:1 | AA large text | Lc -29.0 | 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
#E4EBF0
oklch(93.6% 0.01 238.5)
-
Step 200
200
#CDDBE6
oklch(88.4% 0.021 241.4)
-
Step 300
300
#ABC5D7
oklch(81% 0.038 238.2)
-
Step 400
400
#7EA6C2
oklch(70.6% 0.06 239.2)
-
Step 500
500
#5C90B3
oklch(63.1% 0.077 239.1)
-
Step 600
600 (this color)
#3F799E
oklch(55.3% 0.084 238.8)
-
Step 700
700
#316788
oklch(49.2% 0.078 238)
-
Step 800
800
#2A546E
oklch(42.7% 0.064 237.9)
-
Step 900
900
#274559
oklch(37.6% 0.05 239.2)
-
Step 950
950
#172934
oklch(27.1% 0.031 236.4)
#3F799E 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) | #6879A0 | 0.047 |
| Deuteranopia (no green cones) | #5B6F9D | 0.039 |
| Tritanopia (no blue cones) | #008285 | 0.063 |
| Achromatopsia (no color) | #737373 | 0.084 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F799E
#3F799E
oklch(55.3% 0.084 238.8)
- #97663E
#97663E
oklch(55.3% 0.084 59)
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 #3F799E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.009
- Dull Blue #49759C ΔE 0.014
- Stormy Blue #507B9C ΔE 0.019
- Muted Blue #3B719F ΔE 0.025
- Flat Blue #3C73A8 ΔE 0.027
- Metallic Blue #4F738E ΔE 0.028
- Nice Blue #107AB0 ΔE 0.036
- Ocean #017B92 ΔE 0.039
Use #3F799E 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.