#3F84BB
Closest named color: Cool Blue (#4984B8). oklch(59.3% 0.109 245.2), rgb(63, 132, 187).
Aa
Black text reads best on this color (5.22:1).
About this color
#3F84BB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.109 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.009 away. Black text reads best on it, at 5.22:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.109) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.22:1 |
| White text | 4.01:1 |
Values
| HEX | #3F84BB |
| RGB | rgb(63, 132, 187) |
| HSL | hsl(207, 50%, 49%) |
| OKLCH | oklch(59.3% 0.109 245.2) |
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 #3F84BB | 4.01:1 | AA large text | Lc -72.7 | Content text, not long reading |
| Black text on #3F84BB | 5.22:1 | AA | Lc 36.9 | Non-text elements, placeholder text |
| #3F84BB text on white | 4.01:1 | AA large text | Lc 67.2 | Content text, not long reading |
| #3F84BB text on black | 5.22:1 | AA | Lc -34.5 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#CBDBEA
oklch(88.4% 0.027 246.4)
-
Step 300
300
#A7C5DF
oklch(81% 0.049 244.6)
-
Step 400
400
#77A6CF
oklch(70.7% 0.079 245.5)
-
Step 500
500
#518FC2
oklch(63% 0.101 245.2)
-
Step 600
600 (this color)
#3F84BB
oklch(59.3% 0.109 245.2)
-
Step 700
700
#256596
oklch(49% 0.102 245.4)
-
Step 800
800
#21537A
oklch(42.8% 0.084 245.3)
-
Step 900
900
#204562
oklch(37.7% 0.066 244.5)
-
Step 950
950
#142839
oklch(26.9% 0.041 245.8)
#3F84BB 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) | #6C85BD | 0.048 |
| Deuteranopia (no green cones) | #5B79BA | 0.038 |
| Tritanopia (no blue cones) | #009197 | 0.082 |
| Achromatopsia (no color) | #7F7F7F | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F84BB
#3F84BB
oklch(59.3% 0.109 245.2)
- #AA6F2E
#AA6F2E
oklch(59.2% 0.109 65.2)
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 #3F84BB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.009
- Steel Blue #4682B4 ΔE 0.012
- Off Blue #5684AE ΔE 0.028
- Water Blue #0E87CC ΔE 0.032
- Blue NCS #118AB2 ΔE 0.033
- Dusty Blue #5A86AD ΔE 0.034
- Windows Blue #3778BF ΔE 0.038
- Nice Blue #107AB0 ΔE 0.045
Use #3F84BB 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.