#3B91C8
Closest named color: Cool Blue (#4984B8). oklch(62.9% 0.116 240.4), rgb(59, 145, 200).
Aa
Black text reads best on this color (6.07:1).
About this color
#3B91C8 is a medium-light, moderately saturated blue. In OKLCH its lightness is 63%, its chroma 0.116 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.038 away. Black text reads best on it, at 6.07:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | moderately saturated (0.116) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 6.07:1 |
| White text | 3.45:1 |
Values
| HEX | #3B91C8 |
| RGB | rgb(59, 145, 200) |
| HSL | hsl(203, 56%, 51%) |
| OKLCH | oklch(62.9% 0.116 240.4) |
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 #3B91C8 | 3.45:1 | AA large text | Lc -67.3 | Content text, not long reading |
| Black text on #3B91C8 | 6.07:1 | AA | Lc 42.2 | Non-text elements, placeholder text |
| #3B91C8 text on white | 3.45:1 | AA large text | Lc 61.8 | Content text, not long reading |
| #3B91C8 text on black | 6.07:1 | AA | Lc -39.9 | 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
#E1ECF4
oklch(93.7% 0.016 239.1)
-
Step 200
200
#C7DCEC
oklch(88.4% 0.032 240.7)
-
Step 300
300
#A0C6E2
oklch(80.8% 0.057 240.3)
-
Step 400
400
#6AA8D4
oklch(70.7% 0.091 240.7)
-
Step 500
500 (this color)
#3B91C8
oklch(62.9% 0.116 240.4)
-
Step 600
600
#077BB5
oklch(55.6% 0.126 240.2)
-
Step 700
700
#00679A
oklch(49.1% 0.113 240.5)
-
Step 800
800
#03547F
oklch(42.6% 0.098 241.1)
-
Step 900
900
#124666
oklch(37.7% 0.076 240.7)
-
Step 950
950
#0D293C
oklch(27% 0.049 241.5)
#3B91C8 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) | #7891CA | 0.061 |
| Deuteranopia (no green cones) | #6484C7 | 0.048 |
| Tritanopia (no blue cones) | #009FA4 | 0.081 |
| Achromatopsia (no color) | #8A8A8A | 0.116 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3B91C8
#3B91C8
oklch(62.9% 0.116 240.4)
- #BB7737
#BB7737
oklch(62.9% 0.116 61.1)
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 #3B91C8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.038
- Water Blue #0E87CC ΔE 0.039
- Faded Blue #658CBB ΔE 0.040
- Blue NCS #118AB2 ΔE 0.045
- Steel Blue #4682B4 ΔE 0.046
- Dark Sky Blue #448EE4 ΔE 0.046
- Dusty Blue #5A86AD ΔE 0.048
- Off Blue #5684AE ΔE 0.048
Use #3B91C8 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.