#6379CB
Closest named color: Windows Blue (#3778BF). oklch(59.6% 0.128 270.8), rgb(99, 121, 203).
Aa
Black text reads best on this color (5.12:1).
About this color
#6379CB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.128 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.051 away. Black text reads best on it, at 5.12:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.12:1 |
| White text | 4.09:1 |
Values
| HEX | #6379CB |
| RGB | rgb(99, 121, 203) |
| HSL | hsl(227, 50%, 59%) |
| OKLCH | oklch(59.6% 0.128 270.8) |
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 #6379CB | 4.09:1 | AA large text | Lc -73.5 | Content text, not long reading |
| Black text on #6379CB | 5.12:1 | AA | Lc 36.1 | Non-text elements, placeholder text |
| #6379CB text on white | 4.09:1 | AA large text | Lc 68.0 | Content text, not long reading |
| #6379CB text on black | 5.12:1 | AA | Lc -33.7 | 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 500.
-
Step 50
50
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E5EAF6
oklch(93.7% 0.017 267.8)
-
Step 200
200
#D0D9F1
oklch(88.6% 0.034 269.3)
-
Step 300
300
#B1BFEA
oklch(80.8% 0.063 270.8)
-
Step 400
400
#899DDF
oklch(70.6% 0.1 270.8)
-
Step 500
500 (this color)
#6379CB
oklch(59.6% 0.128 270.8)
-
Step 600
600
#566CC4
oklch(55.7% 0.138 270.8)
-
Step 700
700
#4659A9
oklch(49% 0.129 270.9)
-
Step 800
800
#3A4989
oklch(42.6% 0.107 271.3)
-
Step 900
900
#313E6E
oklch(37.7% 0.084 270.5)
-
Step 950
950
#1D2440
oklch(26.9% 0.053 271.8)
#6379CB 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) | #5882CE | 0.025 |
| Deuteranopia (no green cones) | #4D79C9 | 0.026 |
| Tritanopia (no blue cones) | #358B98 | 0.115 |
| Achromatopsia (no color) | #7D7D7D | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6379CB
#6379CB
oklch(59.6% 0.128 270.8)
- #9B7B00
#9B7B00
oklch(59.7% 0.122 90.4)
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 #6379CB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.051
- Cool Blue #4984B8 ΔE 0.054
- Soft Blue #6488EA ΔE 0.056
- Steel Blue #4682B4 ΔE 0.057
- Off Blue #5684AE ΔE 0.062
- Dark Sky Blue #448EE4 ΔE 0.063
- Faded Blue #658CBB ΔE 0.064
- Water Blue #0E87CC ΔE 0.066
Use #6379CB 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.