#6378CE
Closest named color: Windows Blue (#3778BF). oklch(59.6% 0.133 271.5), rgb(99, 120, 206).
Aa
Black text reads best on this color (5.10:1).
About this color
#6378CE is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.133 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.053 away. Black text reads best on it, at 5.10:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.133) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.10:1 |
| White text | 4.11:1 |
Values
| HEX | #6378CE |
| RGB | rgb(99, 120, 206) |
| HSL | hsl(228, 52%, 60%) |
| OKLCH | oklch(59.6% 0.133 271.5) |
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 #6378CE | 4.11:1 | AA large text | Lc -73.6 | Content text, not long reading |
| Black text on #6378CE | 5.10:1 | AA | Lc 36.0 | Non-text elements, placeholder text |
| #6378CE text on white | 4.11:1 | AA large text | Lc 68.1 | Content text, not long reading |
| #6378CE text on black | 5.10:1 | AA | Lc -33.6 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E5E9F7
oklch(93.5% 0.019 273.2)
-
Step 200
200
#D0D8F2
oklch(88.4% 0.037 272)
-
Step 300
300
#B1BFEC
oklch(80.9% 0.066 271.4)
-
Step 400
400
#899DE2
oklch(70.8% 0.104 271.2)
-
Step 500
500 (this color)
#6378CE
oklch(59.6% 0.133 271.5)
-
Step 600
600
#566BC7
oklch(55.7% 0.144 271.4)
-
Step 700
700
#4658AC
oklch(49% 0.135 271.5)
-
Step 800
800
#3A498B
oklch(42.8% 0.11 271.4)
-
Step 900
900
#313D6F
oklch(37.6% 0.087 271.5)
-
Step 950
950
#1D2441
oklch(26.9% 0.055 272)
#6378CE 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) | #5582D1 | 0.029 |
| Deuteranopia (no green cones) | #4979CC | 0.030 |
| Tritanopia (no blue cones) | #328A99 | 0.118 |
| Achromatopsia (no color) | #7D7D7D | 0.133 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6378CE
#6378CE
oklch(59.6% 0.133 271.5)
- #9A7B00
#9A7B00
oklch(59.6% 0.122 91)
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 #6378CE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.053
- Soft Blue #6488EA ΔE 0.055
- Cool Blue #4984B8 ΔE 0.059
- Steel Blue #4682B4 ΔE 0.062
- Cornflower #6A79F7 ΔE 0.063
- Dark Sky Blue #448EE4 ΔE 0.064
- Dark Periwinkle #665FD1 ΔE 0.064
- Royal Blue #4169E1 ΔE 0.067
Use #6378CE 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.