#3F8DBF
Closest named color: Cool Blue (#4984B8). oklch(61.6% 0.108 239.9), rgb(63, 141, 191).
Aa
Black text reads best on this color (5.77:1).
About this color
#3F8DBF is a medium-dark, moderately saturated blue. In OKLCH its lightness is 62%, its chroma 0.108 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.025 away. Black text reads best on it, at 5.77:1.
| Hue family | Blues |
| Lightness | medium-dark (62%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.77:1 |
| White text | 3.63:1 |
Values
| HEX | #3F8DBF |
| RGB | rgb(63, 141, 191) |
| HSL | hsl(203, 50%, 50%) |
| OKLCH | oklch(61.6% 0.108 239.9) |
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 #3F8DBF | 3.63:1 | AA large text | Lc -69.2 | Content text, not long reading |
| Black text on #3F8DBF | 5.77:1 | AA | Lc 40.4 | Non-text elements, placeholder text |
| #3F8DBF text on white | 3.63:1 | AA large text | Lc 63.7 | Content text, not long reading |
| #3F8DBF text on black | 5.77:1 | AA | Lc -38.0 | 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
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1EBF3
oklch(93.5% 0.015 241.8)
-
Step 200
200
#C9DCEB
oklch(88.5% 0.029 241.6)
-
Step 300
300
#A3C6E0
oklch(81% 0.053 240.5)
-
Step 400
400
#6EA8D0
oklch(70.7% 0.084 239.7)
-
Step 500
500 (this color)
#3F8DBF
oklch(61.6% 0.108 239.9)
-
Step 600
600
#1D7BB0
oklch(55.6% 0.116 239.7)
-
Step 700
700
#0B6798
oklch(49.1% 0.109 240.4)
-
Step 800
800
#10547B
oklch(42.6% 0.091 240.3)
-
Step 900
900
#184663
oklch(37.7% 0.07 240.2)
-
Step 950
950
#0F293A
oklch(26.9% 0.045 240)
#3F8DBF 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) | #768DC1 | 0.057 |
| Deuteranopia (no green cones) | #6481BE | 0.045 |
| Tritanopia (no blue cones) | #009A9E | 0.077 |
| Achromatopsia (no color) | #868686 | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F8DBF
#3F8DBF
oklch(61.6% 0.108 239.9)
- #B4743C
#B4743C
oklch(61.6% 0.108 59.8)
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 #3F8DBF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.025
- Steel Blue #4682B4 ΔE 0.031
- Blue NCS #118AB2 ΔE 0.034
- Off Blue #5684AE ΔE 0.034
- Dusty Blue #5A86AD ΔE 0.035
- Faded Blue #658CBB ΔE 0.036
- Water Blue #0E87CC ΔE 0.038
- Dark Sky Blue #448EE4 ΔE 0.057
Use #3F8DBF 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.