#6371C4
Closest named color: Windows Blue (#3778BF). oklch(57.6% 0.128 274.4), rgb(99, 113, 196).
Aa
Black text reads best on this color (4.68:1).
About this color
#6371C4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.128 and its hue 274°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.050 away. Black text reads best on it, at 4.68:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.68:1 |
| White text | 4.47:1 |
Values
| HEX | #6371C4 |
| RGB | rgb(99, 113, 196) |
| HSL | hsl(231, 45%, 58%) |
| OKLCH | oklch(57.6% 0.128 274.4) |
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 #6371C4 | 4.47:1 | AA large text | Lc -76.4 | Fine for body text |
| Black text on #6371C4 | 4.68:1 | AA | Lc 33.1 | Non-text elements, placeholder text |
| #6371C4 text on white | 4.47:1 | AA large text | Lc 70.9 | Content text, not long reading |
| #6371C4 text on black | 4.68:1 | AA | Lc -30.7 | 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
#F4F5FB
oklch(97.1% 0.008 278.6)
-
Step 100
100
#E6E9F5
oklch(93.5% 0.016 274.8)
-
Step 200
200
#D2D8EF
oklch(88.5% 0.032 274.1)
-
Step 300
300
#B5BEE7
oklch(80.8% 0.059 275.3)
-
Step 400
400
#8F9CDA
oklch(70.6% 0.092 274.7)
-
Step 500
500
#7483D0
oklch(63.1% 0.117 274.2)
-
Step 600
600 (this color)
#6371C4
oklch(57.6% 0.128 274.4)
-
Step 700
700
#4D59A3
oklch(49.1% 0.119 274.3)
-
Step 800
800
#3F4984
oklch(42.7% 0.098 274.2)
-
Step 900
900
#353D6A
oklch(37.5% 0.078 274.4)
-
Step 950
950
#1F243E
oklch(26.9% 0.049 274.4)
#6371C4 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) | #507BC7 | 0.032 |
| Deuteranopia (no green cones) | #4673C2 | 0.034 |
| Tritanopia (no blue cones) | #3C8391 | 0.114 |
| Achromatopsia (no color) | #777777 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6371C4
#6371C4
oklch(57.6% 0.128 274.4)
- #907700
#907700
oklch(57.6% 0.118 94.2)
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 #6371C4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.050
- Dark Periwinkle #665FD1 ΔE 0.052
- French Blue #436BAD ΔE 0.057
- Slate Blue #6A5ACD ΔE 0.061
- Light Indigo #6D5ACF ΔE 0.062
- Cool Blue #4984B8 ΔE 0.064
- Iris #6258C4 ΔE 0.064
- Steel Blue #4682B4 ΔE 0.064
Use #6371C4 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.