#643fcc
a balanced, vivid violet · cool · closest name: Blue Violet
At a glance
Every number on this page in one read: what #643fcc is made of, how bright it looks, and which way it leans.
Reads cool. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.
Every format
| HEX | #643fcc |
| RGB | rgb(100, 63, 204) |
| HSL | hsl(256, 58%, 52%) |
| CMYK | cmyk(51%, 69%, 0%, 20%) |
| LAB | lab(38.9 50.0 -67.6) |
| LCH | lch(38.9 84.1 306.5) |
| OKLCH | oklch(0.495 0.205 288.6) |
| Decimal | 6569932 |
| Display P3 | color(display-p3 0.392 0.247 0.800) |
Copy-ready code
/* CSS */
color: #643fcc;
background-color: #643fcc;
/* Tailwind (arbitrary) */
class="text-[#643fcc] bg-[#643fcc]"
/* SCSS */
$brand: #643fcc;
/* SwiftUI */
Color(red: 0.392, green: 0.247, blue: 0.800)
/* Android */
Color.parseColor("#643fcc")
/* Flutter */
Color(0xFF643FCC)
/* Python / OpenCV (BGR) */
(204, 63, 100)Best text color
Only one of black and white can be right. This is the one, with the number that proves it.
Accessibility — WCAG contrast
Color scale — 50 to 950
A Tailwind-shaped ramp built around this exact hex. #643fcc is pinned to step 500; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.
:root {
--brand-50: #F6F4FB;
--brand-100: #ECE9F7;
--brand-200: #D6CDEF;
--brand-300: #B7A6E7;
--brand-400: #947ADC;
--brand-500: #643fcc;
--brand-600: #5933C1;
--brand-700: #4A2BA1;
--brand-800: #3B2281;
--brand-900: #2E1D5E;
--brand-950: #1D123B;
--brand: #643fcc;
--brand-ink: #ffffff;
}Colors that work with #643fcc
Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.
Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.
Lightness flips, hue holds. The accent stays the anchor in both themes.
How to use #643fcc
Derived from its contrast, chroma and lightness — not from taste.
- ✓Body text and links on white
- ✓Primary buttons and calls to action
- ✓Focus rings, active and selected states
- ✓Brand accents, badges and data highlights
- ⚠Full-page backgrounds — tiring over long sessions
- ⚠Pairing with a same-lightness hue — edges vibrate
Similar colors
One move away from this hex in each direction. Every swatch is its own page.
Color relationships
The wheel positions with their names attached, so you can grab the one you actually need.
| Complementary | #A7CC3F | Directly opposite — maximum tension | |
| Analogous left | #3F61CC | Neighbour, quieter | |
| Analogous right | #AA3FCC | Neighbour, quieter | |
| Split-complement 1 | #CCAA3F | Contrast without the clash | |
| Split-complement 2 | #61CC3F | Contrast without the clash | |
| Triadic 1 | #CC643F | Even thirds — balanced and loud | |
| Triadic 2 | #3FCC64 | Even thirds — balanced and loud | |
| Tetradic | #CC3F61 | Fourth corner of the square scheme |
RGB percentages
CMYK percentages
Color previews
#643fcc text on a black background
contrast 3.12:1
#643fcc text on a white background
contrast 6.72:1
CSS3 live lab
The quick brown fox
color: #643fcc;
background-color: #643fcc;
Glowing headline
text-shadow: 2px 2px 8px #643fcc;
Soft neon halo
text-shadow: 0 0 14px rgba(100, 63, 204, 0.45);
box-shadow: 0 12px 32px -8px rgba(100, 63, 204, 0.45);
border: 3px solid #643fcc; background: linear-gradient(135deg, #643fcc, #C23FCC);
Monochromatic scale
Palettes built from #643fcc
Shades — darker
Tints — lighter
Color harmonies
Nearest named colors
Ranked with CIEDE2000 across all 139 CSS keywords. Under ΔE 2 the eye stops telling them apart; over ΔE 10 they are plainly different colors.
Closest color with a full write-up: Iris (#5a4fcf) — ΔE2000 4.6 away, with its history, psychology and brand usage.
#643fcc in the real world
Where a color in this family tends to land, and the interface roles it is usually asked to play.
Converts to four-color process without much drama. Proof it anyway.
#643fcc, answered
What color is #643fcc?
#643fcc is a balanced vivid violet, closest to Blue Violet (ΔE2000 6.7). It sits at 256° on the hue wheel with 58% saturation and 52% lightness, which reads as cool.
What is the RGB value of #643fcc?
rgb(100, 63, 204) — 100 red, 63 green and 204 blue out of 255, or 39.2% / 24.7% / 80% by channel.
Is #643fcc a light or a dark color?
It is a dark color. Relative luminance is 0.1062 and perceived brightness is 39%, so white text on it reaches 6.72:1.
Should I use black or white text on #643fcc?
White. It scores 6.72:1 against #643fcc, versus 3.12:1 for black — AA at any size.
What is the complementary color of #643fcc?
#A7CC3F sits directly opposite on the wheel. Softer options are the split-complements #CCAA3F and #61CC3F, which give the same contrast with far less vibration.
What colors go well with #643fcc?
For interface work: #F6F4FA as the surface, #CCC0ED for borders, #604B9B for secondary text, #A4A527 as an accent and #2E1B65 for hover and pressed states. For a palette, the analogous pair #3F61CC and #AA3FCC stays calm, while #A7CC3F is the loudest partner.
What is #643fcc in CMYK for printing?
cmyk(51%, 69%, 0%, 20%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.
Is #643fcc warm or cool?
Cool — it scores 75 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #983FCC; nudged cooler, #3D4CCE.