#3181B3
Closest named color: Steel Blue (#4682B4). oklch(57.7% 0.109 240.1), rgb(49, 129, 179).
Aa
Black text reads best on this color (4.92:1).
About this color
#3181B3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.109 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.017 away. Black text reads best on it, at 4.92:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.109) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.92:1 |
| White text | 4.26:1 |
Values
| HEX | #3181B3 |
| RGB | rgb(49, 129, 179) |
| HSL | hsl(203, 57%, 45%) |
| OKLCH | oklch(57.7% 0.109 240.1) |
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 #3181B3 | 4.26:1 | AA large text | Lc -74.7 | Content text, not long reading |
| Black text on #3181B3 | 4.92:1 | AA | Lc 34.9 | Non-text elements, placeholder text |
| #3181B3 text on white | 4.26:1 | AA large text | Lc 69.2 | Content text, not long reading |
| #3181B3 text on black | 4.92:1 | AA | Lc -32.5 | 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
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#CADCEA
oklch(88.5% 0.027 241.2)
-
Step 300
300
#A5C5DE
oklch(80.8% 0.049 241.8)
-
Step 400
400
#73A7CD
oklch(70.6% 0.078 241)
-
Step 500
500
#4B91C0
oklch(63.1% 0.1 240.3)
-
Step 600
600 (this color)
#3181B3
oklch(57.7% 0.109 240.1)
-
Step 700
700
#1B6794
oklch(49.1% 0.101 240.3)
-
Step 800
800
#1A5478
oklch(42.7% 0.084 240.5)
-
Step 900
900
#1C4661
oklch(37.8% 0.066 240)
-
Step 950
950
#122939
oklch(27% 0.042 241)
#3181B3 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) | #6A81B5 | 0.057 |
| Deuteranopia (no green cones) | #5875B2 | 0.045 |
| Tritanopia (no blue cones) | #008E92 | 0.075 |
| Achromatopsia (no color) | #7A7A7A | 0.109 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3181B3
#3181B3
oklch(57.7% 0.109 240.1)
- #A8692F
#A8692F
oklch(57.9% 0.109 60.3)
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 #3181B3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.017
- Cool Blue #4984B8 ΔE 0.024
- Blue NCS #118AB2 ΔE 0.028
- Nice Blue #107AB0 ΔE 0.028
- Windows Blue #3778BF ΔE 0.035
- Cerulean #457B9D ΔE 0.035
- Off Blue #5684AE ΔE 0.035
- Water Blue #0E87CC ΔE 0.039
Use #3181B3 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.