#3F91BC
Closest named color: Cool Blue (#4984B8). oklch(62.4% 0.102 234.7), rgb(63, 145, 188).
Aa
Black text reads best on this color (5.98:1).
About this color
#3F91BC is a medium-light, moderately saturated blue. In OKLCH its lightness is 62%, its chroma 0.102 and its hue 235°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.036 away. Black text reads best on it, at 5.98:1.
| Hue family | Blues |
| Lightness | medium-light (62%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.98:1 |
| White text | 3.50:1 |
Values
| HEX | #3F91BC |
| RGB | rgb(63, 145, 188) |
| HSL | hsl(201, 50%, 49%) |
| OKLCH | oklch(62.4% 0.102 234.7) |
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 #3F91BC | 3.50:1 | AA large text | Lc -67.9 | Content text, not long reading |
| Black text on #3F91BC | 5.98:1 | AA | Lc 41.7 | Non-text elements, placeholder text |
| #3F91BC text on white | 3.50:1 | AA large text | Lc 62.4 | Content text, not long reading |
| #3F91BC text on black | 5.98:1 | AA | Lc -39.3 | 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
#F1F6F9
oklch(97% 0.007 233.6)
-
Step 100
100
#E1ECF2
oklch(93.7% 0.014 231.2)
-
Step 200
200
#C8DDE9
oklch(88.6% 0.028 232.7)
-
Step 300
300
#A2C7DD
oklch(81% 0.05 234.3)
-
Step 400
400
#6DA9CB
oklch(70.7% 0.08 234.4)
-
Step 500
500 (this color)
#3F91BC
oklch(62.4% 0.102 234.7)
-
Step 600
600
#167DAA
oklch(55.7% 0.11 234.1)
-
Step 700
700
#016992
oklch(49.1% 0.103 234.3)
-
Step 800
800
#0C5677
oklch(42.8% 0.086 234.6)
-
Step 900
900
#164760
oklch(37.8% 0.067 234.9)
-
Step 950
950
#0F2A38
oklch(27.1% 0.042 233.9)
#3F91BC 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) | #7C90BE | 0.063 |
| Deuteranopia (no green cones) | #6B83BB | 0.054 |
| Tritanopia (no blue cones) | #009C9F | 0.067 |
| Achromatopsia (no color) | #898989 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F91BC
#3F91BC
oklch(62.4% 0.102 234.7)
- #B77648
#B77648
oklch(62.5% 0.102 54.9)
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 #3F91BC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.036
- Blue NCS #118AB2 ΔE 0.036
- Faded Blue #658CBB ΔE 0.036
- Dusty Blue #5A86AD ΔE 0.037
- Off Blue #5684AE ΔE 0.039
- Steel Blue #4682B4 ΔE 0.041
- Water Blue #0E87CC ΔE 0.049
- Teal Blue #01889F ΔE 0.059
Use #3F91BC 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.