#3178A4
Closest named color: Flat Blue (#3C73A8). oklch(54.8% 0.098 239.4), rgb(49, 120, 164).
Aa
White text reads best on this color (4.82:1).
About this color
#3178A4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.098 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Flat Blue (#3C73A8), ΔE 0.019 away. White text reads best on it, at 4.82:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Flat Blue (#3C73A8) |
| Black text | 4.35:1 |
| White text | 4.82:1 |
Values
| HEX | #3178A4 |
| RGB | rgb(49, 120, 164) |
| HSL | hsl(203, 54%, 42%) |
| OKLCH | oklch(54.8% 0.098 239.4) |
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 #3178A4 | 4.82:1 | AA | Lc -78.6 | Fine for body text |
| Black text on #3178A4 | 4.35:1 | AA large text | Lc 30.9 | Non-text elements, placeholder text |
| #3178A4 text on white | 4.82:1 | AA | Lc 73.2 | Content text, not long reading |
| #3178A4 text on black | 4.35:1 | AA large text | Lc -28.5 | 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
#E3EBF2
oklch(93.6% 0.013 244.3)
-
Step 200
200
#CBDCE8
oklch(88.5% 0.025 238.4)
-
Step 300
300
#A7C5DB
oklch(80.8% 0.045 239.9)
-
Step 400
400
#77A7C8
oklch(70.6% 0.071 239.1)
-
Step 500
500
#5291BA
oklch(63.1% 0.09 238.9)
-
Step 600
600 (this color)
#3178A4
oklch(54.8% 0.098 239.4)
-
Step 700
700
#25678F
oklch(49.1% 0.092 239.4)
-
Step 800
800
#215474
oklch(42.7% 0.076 239.6)
-
Step 900
900
#21465E
oklch(37.8% 0.059 239.4)
-
Step 950
950
#142937
oklch(27% 0.038 239.4)
#3178A4 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) | #6478A6 | 0.053 |
| Deuteranopia (no green cones) | #546DA3 | 0.043 |
| Tritanopia (no blue cones) | #008387 | 0.068 |
| Achromatopsia (no color) | #727272 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3178A4
#3178A4
oklch(54.8% 0.098 239.4)
- #9B6230
#9B6230
oklch(54.9% 0.099 59.6)
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 #3178A4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Flat Blue #3C73A8 ΔE 0.019
- Muted Blue #3B719F ΔE 0.020
- Nice Blue #107AB0 ΔE 0.022
- Dull Blue #49759C ΔE 0.023
- Cerulean #457B9D ΔE 0.023
- Stormy Blue #507B9C ΔE 0.033
- Ocean Blue #03719C ΔE 0.034
- Sea Blue #047495 ΔE 0.035
Use #3178A4 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.