#3978A1
Closest named color: Dull Blue (#49759C). oklch(54.9% 0.091 239.9), rgb(57, 120, 161).
Aa
White text reads best on this color (4.79:1).
About this color
#3978A1 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.091 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Dull Blue (#49759C), ΔE 0.016 away. White text reads best on it, at 4.79:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.091) |
| Temperature | cool |
| Nearest name | Dull Blue (#49759C) |
| Black text | 4.37:1 |
| White text | 4.79:1 |
Values
| HEX | #3978A1 |
| RGB | rgb(57, 120, 161) |
| HSL | hsl(204, 48%, 43%) |
| OKLCH | oklch(54.9% 0.091 239.9) |
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 #3978A1 | 4.79:1 | AA | Lc -78.5 | Fine for body text |
| Black text on #3978A1 | 4.37:1 | AA large text | Lc 31.0 | Non-text elements, placeholder text |
| #3978A1 text on white | 4.79:1 | AA | Lc 73.1 | Content text, not long reading |
| #3978A1 text on black | 4.37:1 | AA large text | Lc -28.6 | 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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E3EBF1
oklch(93.6% 0.012 239.9)
-
Step 200
200
#CCDCE7
oklch(88.6% 0.023 237.7)
-
Step 300
300
#AAC5D9
oklch(81% 0.041 240.1)
-
Step 400
400
#7BA7C6
oklch(70.8% 0.066 239.6)
-
Step 500
500
#5890B7
oklch(63% 0.084 240.3)
-
Step 600
600 (this color)
#3978A1
oklch(54.9% 0.091 239.9)
-
Step 700
700
#2D678C
oklch(49.2% 0.085 239.7)
-
Step 800
800
#265471
oklch(42.7% 0.07 239)
-
Step 900
900
#24455C
oklch(37.6% 0.055 240.8)
-
Step 950
950
#162936
oklch(27.1% 0.035 239.7)
#3978A1 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) | #6578A3 | 0.049 |
| Deuteranopia (no green cones) | #576EA0 | 0.039 |
| Tritanopia (no blue cones) | #008286 | 0.065 |
| Achromatopsia (no color) | #727272 | 0.091 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3978A1
#3978A1
oklch(54.9% 0.091 239.9)
- #986437
#986437
oklch(55% 0.091 60.1)
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 #3978A1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dull Blue #49759C ΔE 0.016
- Cerulean #457B9D ΔE 0.017
- Muted Blue #3B719F ΔE 0.020
- Flat Blue #3C73A8 ΔE 0.021
- Stormy Blue #507B9C ΔE 0.026
- Nice Blue #107AB0 ΔE 0.029
- Metallic Blue #4F738E ΔE 0.034
- Sea Blue #047495 ΔE 0.037
Use #3978A1 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.