#3F74A3
Closest named color: Flat Blue (#3C73A8). oklch(54.3% 0.093 247.2), rgb(63, 116, 163).
Aa
White text reads best on this color (4.95:1).
About this color
#3F74A3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 54%, its chroma 0.093 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Flat Blue (#3C73A8), ΔE 0.009 away. White text reads best on it, at 4.95:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | moderately saturated (0.093) |
| Temperature | cool |
| Nearest name | Flat Blue (#3C73A8) |
| Black text | 4.23:1 |
| White text | 4.95:1 |
Values
| HEX | #3F74A3 |
| RGB | rgb(63, 116, 163) |
| HSL | hsl(208, 44%, 44%) |
| OKLCH | oklch(54.3% 0.093 247.2) |
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 #3F74A3 | 4.95:1 | AA | Lc -79.5 | Fine for body text |
| Black text on #3F74A3 | 4.23:1 | AA large text | Lc 30.0 | Dividers and decoration only |
| #3F74A3 text on white | 4.95:1 | AA | Lc 74.1 | Content text, not long reading |
| #3F74A3 text on black | 4.23:1 | AA large text | Lc -27.6 | 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
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E4EBF2
oklch(93.7% 0.012 248)
-
Step 200
200
#CDDBE8
oklch(88.5% 0.023 246.1)
-
Step 300
300
#ACC4DB
oklch(81% 0.042 247.2)
-
Step 400
400
#7FA5C9
oklch(70.7% 0.067 247.4)
-
Step 500
500
#5E8EBB
oklch(63.1% 0.086 247.8)
-
Step 600
600 (this color)
#3F74A3
oklch(54.3% 0.093 247.2)
-
Step 700
700
#34658F
oklch(49.2% 0.086 246.6)
-
Step 800
800
#2C5274
oklch(42.6% 0.072 247.3)
-
Step 900
900
#28445E
oklch(37.7% 0.056 247.8)
-
Step 950
950
#182837
oklch(27% 0.035 247.7)
#3F74A3 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) | #6075A5 | 0.038 |
| Deuteranopia (no green cones) | #526CA2 | 0.028 |
| Tritanopia (no blue cones) | #007F84 | 0.075 |
| Achromatopsia (no color) | #707070 | 0.093 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F74A3
#3F74A3
oklch(54.3% 0.093 247.2)
- #94642E
#94642E
oklch(54.4% 0.093 66.7)
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 #3F74A3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Flat Blue #3C73A8 ΔE 0.009
- Muted Blue #3B719F ΔE 0.011
- Dull Blue #49759C ΔE 0.015
- Cerulean #457B9D ΔE 0.026
- Nice Blue #107AB0 ΔE 0.032
- Stormy Blue #507B9C ΔE 0.032
- French Blue #436BAD ΔE 0.033
- Metallic Blue #4F738E ΔE 0.035
Use #3F74A3 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.