#3181B2
Closest named color: Steel Blue (#4682B4). oklch(57.7% 0.107 239.6), rgb(49, 129, 178).
Aa
Black text reads best on this color (4.91:1).
About this color
#3181B2 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.107 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.018 away. Black text reads best on it, at 4.91:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.107) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.91:1 |
| White text | 4.27:1 |
Values
| HEX | #3181B2 |
| RGB | rgb(49, 129, 178) |
| HSL | hsl(203, 57%, 45%) |
| OKLCH | oklch(57.7% 0.107 239.6) |
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 #3181B2 | 4.27:1 | AA large text | Lc -74.7 | Content text, not long reading |
| Black text on #3181B2 | 4.91:1 | AA | Lc 34.8 | Non-text elements, placeholder text |
| #3181B2 text on white | 4.27:1 | AA large text | Lc 69.2 | Content text, not long reading |
| #3181B2 text on black | 4.91:1 | AA | Lc -32.4 | 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
#E2EBF2
oklch(93.5% 0.014 241)
-
Step 200
200
#CADCE9
oklch(88.5% 0.026 239.1)
-
Step 300
300
#A5C6DD
oklch(81% 0.048 238.6)
-
Step 400
400
#73A8CC
oklch(70.8% 0.077 239)
-
Step 500
500
#4B91BF
oklch(63% 0.099 239.7)
-
Step 600
600 (this color)
#3181B2
oklch(57.7% 0.107 239.6)
-
Step 700
700
#1B6793
oklch(49% 0.1 239.7)
-
Step 800
800
#1A5477
oklch(42.6% 0.082 239.7)
-
Step 900
900
#1C4660
oklch(37.7% 0.064 238.9)
-
Step 950
950
#122938
oklch(27% 0.04 239.2)
#3181B2 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) | #6A81B4 | 0.057 |
| Deuteranopia (no green cones) | #5875B1 | 0.045 |
| Tritanopia (no blue cones) | #008D92 | 0.072 |
| Achromatopsia (no color) | #7A7A7A | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3181B2
#3181B2
oklch(57.7% 0.107 239.6)
- #A76830
#A76830
oklch(57.6% 0.108 59.5)
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 #3181B2, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.018
- Cool Blue #4984B8 ΔE 0.024
- Blue NCS #118AB2 ΔE 0.027
- Nice Blue #107AB0 ΔE 0.028
- Cerulean #457B9D ΔE 0.034
- Off Blue #5684AE ΔE 0.035
- Windows Blue #3778BF ΔE 0.036
- Flat Blue #3C73A8 ΔE 0.039
Use #3181B2 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.