#3F87BB
Closest named color: Cool Blue (#4984B8). oklch(60% 0.107 242.8), rgb(63, 135, 187).
Aa
Black text reads best on this color (5.39:1).
About this color
#3F87BB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.107 and its hue 243°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.011 away. Black text reads best on it, at 5.39:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.107) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.39:1 |
| White text | 3.89:1 |
Values
| HEX | #3F87BB |
| RGB | rgb(63, 135, 187) |
| HSL | hsl(205, 50%, 49%) |
| OKLCH | oklch(60% 0.107 242.8) |
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 #3F87BB | 3.89:1 | AA large text | Lc -71.6 | Content text, not long reading |
| Black text on #3F87BB | 5.39:1 | AA | Lc 38.0 | Non-text elements, placeholder text |
| #3F87BB text on white | 3.89:1 | AA large text | Lc 66.1 | Content text, not long reading |
| #3F87BB text on black | 5.39:1 | AA | Lc -35.5 | 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 500.
-
Step 50
50
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#C9DCEB
oklch(88.5% 0.029 241.6)
-
Step 300
300
#A4C5E0
oklch(80.8% 0.052 243.1)
-
Step 400
400
#71A7D1
oklch(70.7% 0.084 242.8)
-
Step 500
500 (this color)
#3F87BB
oklch(60% 0.107 242.8)
-
Step 600
600
#267AB2
oklch(55.7% 0.117 242.8)
-
Step 700
700
#176699
oklch(49.1% 0.109 243.2)
-
Step 800
800
#17547C
oklch(42.8% 0.09 242.5)
-
Step 900
900
#1B4564
oklch(37.6% 0.071 243.7)
-
Step 950
950
#11293A
oklch(27% 0.044 241.7)
#3F87BB 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) | #7088BD | 0.052 |
| Deuteranopia (no green cones) | #5F7CBA | 0.041 |
| Tritanopia (no blue cones) | #009499 | 0.079 |
| Achromatopsia (no color) | #818181 | 0.107 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F87BB
#3F87BB
oklch(60% 0.107 242.8)
- #AD7135
#AD7135
oklch(60.1% 0.107 63.1)
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 #3F87BB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.011
- Steel Blue #4682B4 ΔE 0.016
- Off Blue #5684AE ΔE 0.026
- Blue NCS #118AB2 ΔE 0.030
- Dusty Blue #5A86AD ΔE 0.031
- Water Blue #0E87CC ΔE 0.033
- Faded Blue #658CBB ΔE 0.042
- Windows Blue #3778BF ΔE 0.046
Use #3F87BB 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.