#3178B3
Closest named color: Nice Blue (#107AB0). oklch(55.6% 0.116 247), rgb(49, 120, 179).
Aa
White text reads best on this color (4.69:1).
About this color
#3178B3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.116 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Nice Blue (#107AB0), ΔE 0.017 away. White text reads best on it, at 4.69:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.116) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.46:1 |
| White text | 4.69:1 |
Values
| HEX | #3178B3 |
| RGB | rgb(49, 120, 179) |
| HSL | hsl(207, 57%, 45%) |
| OKLCH | oklch(55.6% 0.116 247) |
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 #3178B3 | 4.69:1 | AA | Lc -77.8 | Fine for body text |
| Black text on #3178B3 | 4.46:1 | AA large text | Lc 31.7 | Non-text elements, placeholder text |
| #3178B3 text on white | 4.69:1 | AA | Lc 72.3 | Content text, not long reading |
| #3178B3 text on black | 4.46:1 | AA large text | Lc -29.3 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF4
oklch(93.6% 0.016 248)
-
Step 200
200
#CADBEC
oklch(88.4% 0.03 248.2)
-
Step 300
300
#A6C4E1
oklch(80.8% 0.052 247.6)
-
Step 400
400
#75A6D2
oklch(70.7% 0.083 246.4)
-
Step 500
500
#508FC6
oklch(63.1% 0.106 246.8)
-
Step 600
600 (this color)
#3178B3
oklch(55.6% 0.116 247)
-
Step 700
700
#23659A
oklch(49.2% 0.107 246.8)
-
Step 800
800
#1F527D
oklch(42.6% 0.09 247.4)
-
Step 900
900
#1F4464
oklch(37.5% 0.07 247.1)
-
Step 950
950
#13283B
oklch(26.9% 0.045 247.5)
#3178B3 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) | #5D7AB6 | 0.045 |
| Deuteranopia (no green cones) | #4B6EB2 | 0.033 |
| Tritanopia (no blue cones) | #00868D | 0.085 |
| Achromatopsia (no color) | #747474 | 0.116 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3178B3
#3178B3
oklch(55.6% 0.116 247)
- #A06414
#A06414
oklch(55.7% 0.116 67)
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 #3178B3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.017
- Windows Blue #3778BF ΔE 0.020
- Flat Blue #3C73A8 ΔE 0.020
- Muted Blue #3B719F ΔE 0.033
- Steel Blue #4682B4 ΔE 0.036
- French Blue #436BAD ΔE 0.037
- Dull Blue #49759C ΔE 0.039
- Cerulean #457B9D ΔE 0.041
Use #3178B3 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.