Recognised as Colour

#B10021

#B10021
Red
Dark
Nearest: Firebrick

#B10021 is a red with RGB values 177, 0, 33 and HSL 349°, 100%, 35%. It is a dark colour, so white text on it reaches 7.3:1 contrast (AAA for normal text). The nearest named colour is Firebrick.

Colour values

#B10021#B10021

HEX#B10021

RGBrgb(177, 0, 33)

RGB (0–1)0.6941, 0, 0.1294

RGB percentages69.4%, 0%, 12.9%

HSLhsl(348.8, 100%, 34.7%)

HSV / HSBhsv(348.8, 100%, 69.4%)

CMYK0%, 100%, 81.4%, 30.6%≈naive device-independent conversion; real print needs an ICC profile

24-bit integer11,599,905

CSS custom property--colour: #B10021;

Brightness & contrast

Relative luminance0.09457WCAG 2.x, 0 is black and 1 is white

Perceived brightness97.4 of 255ITU-R BT.601 weighting

Light or darkDark

Best text colour on this backgroundWhitecontrast 7.26:1

Contrast with white7.26:1WCAG normal text: AAA

Contrast with black2.89:1WCAG normal text: Fail

Greyscale equivalent#282828

Inverted#4EFFDE

Colour vision & accessibility

Normal vision Protanopia Deuteranopia Tritanopia

Protanopia#474020no red cones; affects about 1% of men; ΔE 66.1 from the original

Deuteranopia#6F6319no green cones; the most common form, about 1% of men; ΔE 65.9 from the original

Tritanopia#C40013no blue cones; rare, and affects men and women equally; ΔE 13.7 from the original

Distinguishable without hueShifts in lightness toonever rely on hue alone to carry meaning

Contrast with white, large text7.26:1WCAG large text: AAA

Contrast with black, large text2.89:1WCAG large text: Fail

Named colours

Firebrick · ΔE 6.2 Brown · ΔE 12.9 Crimson · ΔE 14.1 Dark red · ΔE 14.7 Maroon · ΔE 17.7 Indian red · ΔE 27.2

Nearest named CSS colourFirebrick (#B22222)ΔE 6.24, clearly different but related

Hue familyred

CSS keyword usableNo exact keyword

Colour harmonies

base +30°+90°+120°+180°+210°+240°+270°+330°

Complementary#00B190

Analogous#B1007A, #B13700

Triadic#21B100, #0021B1

Split complementary#00B137, #007AB1

Tetradic#7AB100, #00B190, #3700B1

Tints, shades & saturation

+40%+30%+20%+10%base -10%-20%-30%-40%

Lighter +40%#FF7E96

Lighter +30%#FF4B6D

Lighter +20%#FF1843

Lighter +10%#E4002B

Darker −10%#7E0017

Darker −20%#4B000E

Darker −30%#180004

Darker −40%#000000

More saturated +25%#B10021

Less saturated −25%#9B162F

Channel breakdown

R177

B33

Red177 (69.4%)

Green0 (0%)

Blue33 (12.9%)

Hue348.81°

Saturation (HSL)100%

Lightness34.71%

Dominant channelRed

Hex per channelR B1 · G 00 · B 21

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Harmonies

Lighter and darker

Similar named colours

Also reads as

B10021 (chemical formula)

Formula
108,327.01 g/mol
10021 atoms

B10021 has a molar mass of 108,327.01 g/mol, made up of 10021 atoms across 1 element: 10021 × B.

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Molar mass

Molar mass108,327.01 g/mol

Total atoms per molecule10021

Distinct elements1

Mass of one molecule1.7988123 × 10^-19 g

Molecules per gram5.5592237 × 10^18

Name

NameNot in the name tablea name cannot be worked out from a formula alone: isomers share formulas, and naming depends on bonding the formula does not show

Composition by mass

B100%

Boron (B × 10021)108,327.01 g/mol, 100%

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Elements in this formula

Boron

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