#3F7DA4
Closest named color: Cerulean (#457B9D). oklch(56.5% 0.088 238.6), rgb(63, 125, 164).
Aa
Black text reads best on this color (4.68:1).
About this color
#3F7DA4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.088 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.011 away. Black text reads best on it, at 4.68:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.088) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.68:1 |
| White text | 4.48:1 |
Values
| HEX | #3F7DA4 |
| RGB | rgb(63, 125, 164) |
| HSL | hsl(203, 44%, 45%) |
| OKLCH | oklch(56.5% 0.088 238.6) |
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 #3F7DA4 | 4.48:1 | AA large text | Lc -76.4 | Fine for body text |
| Black text on #3F7DA4 | 4.68:1 | AA | Lc 33.1 | Non-text elements, placeholder text |
| #3F7DA4 text on white | 4.48:1 | AA large text | Lc 71.0 | Content text, not long reading |
| #3F7DA4 text on black | 4.68:1 | AA | Lc -30.7 | Non-text elements, placeholder text |
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
#CCDCE6
oklch(88.5% 0.022 235)
-
Step 300
300
#AAC5D8
oklch(80.9% 0.04 238.7)
-
Step 400
400
#7CA7C4
oklch(70.8% 0.063 238.3)
-
Step 500
500
#5991B5
oklch(63.2% 0.08 238.1)
-
Step 600
600 (this color)
#3F7DA4
oklch(56.5% 0.088 238.6)
-
Step 700
700
#2E678A
oklch(49.2% 0.082 238.5)
-
Step 800
800
#275470
oklch(42.7% 0.068 238.5)
-
Step 900
900
#25455B
oklch(37.6% 0.054 240.3)
-
Step 950
950
#162935
oklch(27.1% 0.033 237.5)
#3F7DA4 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) | #6B7DA6 | 0.050 |
| Deuteranopia (no green cones) | #5D72A3 | 0.042 |
| Tritanopia (no blue cones) | #00878A | 0.065 |
| Achromatopsia (no color) | #777777 | 0.088 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F7DA4
#3F7DA4
oklch(56.5% 0.088 238.6)
- #9D693F
#9D693F
oklch(56.7% 0.088 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 #3F7DA4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.011
- Stormy Blue #507B9C ΔE 0.019
- Dull Blue #49759C ΔE 0.024
- Steel Blue #4682B4 ΔE 0.028
- Flat Blue #3C73A8 ΔE 0.032
- Nice Blue #107AB0 ΔE 0.035
- Off Blue #5684AE ΔE 0.035
- Muted Blue #3B719F ΔE 0.035
Use #3F7DA4 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.