#3F7DAA
Closest named color: Cerulean (#457B9D). oklch(56.8% 0.095 242.5), rgb(63, 125, 170).
Aa
Black text reads best on this color (4.72:1).
About this color
#3F7DAA is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.095 and its hue 242°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.020 away. Black text reads best on it, at 4.72:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.095) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.72:1 |
| White text | 4.44:1 |
Values
| HEX | #3F7DAA |
| RGB | rgb(63, 125, 170) |
| HSL | hsl(205, 46%, 46%) |
| OKLCH | oklch(56.8% 0.095 242.5) |
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 #3F7DAA | 4.44:1 | AA large text | Lc -76.1 | Fine for body text |
| Black text on #3F7DAA | 4.72:1 | AA | Lc 33.4 | Non-text elements, placeholder text |
| #3F7DAA text on white | 4.44:1 | AA large text | Lc 70.6 | Content text, not long reading |
| #3F7DAA text on black | 4.72:1 | AA | Lc -31.0 | 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
#E3EBF2
oklch(93.6% 0.013 244.3)
-
Step 200
200
#CCDBE8
oklch(88.4% 0.024 244.2)
-
Step 300
300
#A9C5DA
oklch(80.9% 0.042 240.5)
-
Step 400
400
#7BA6C8
oklch(70.7% 0.068 242.7)
-
Step 500
500
#5890BA
oklch(63.2% 0.087 242.3)
-
Step 600
600 (this color)
#3F7DAA
oklch(56.8% 0.095 242.5)
-
Step 700
700
#2D668E
oklch(49.1% 0.088 242.2)
-
Step 800
800
#275374
oklch(42.7% 0.073 243.4)
-
Step 900
900
#24455D
oklch(37.7% 0.057 241.9)
-
Step 950
950
#162937
oklch(27.2% 0.036 241.7)
#3F7DAA 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) | #697DAC | 0.047 |
| Deuteranopia (no green cones) | #5A73A9 | 0.037 |
| Tritanopia (no blue cones) | #00888C | 0.072 |
| Achromatopsia (no color) | #787878 | 0.095 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F7DAA
#3F7DAA
oklch(56.8% 0.095 242.5)
- #9E6937
#9E6937
oklch(56.7% 0.095 62.2)
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 #3F7DAA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.020
- Steel Blue #4682B4 ΔE 0.021
- Stormy Blue #507B9C ΔE 0.025
- Dull Blue #49759C ΔE 0.027
- Flat Blue #3C73A8 ΔE 0.029
- Cool Blue #4984B8 ΔE 0.030
- Nice Blue #107AB0 ΔE 0.031
- Off Blue #5684AE ΔE 0.033
Use #3F7DAA 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.