Recognised as Colour

#B21705

#B21705
Red
Dark
Nearest: Firebrick

#B21705 is a red with RGB values 178, 23, 5 and HSL 6°, 95%, 36%. It is a dark colour, so white text on it reaches 7:1 contrast (AA for normal text). The nearest named colour is Firebrick.

Colour values

#B21705#B21705

HEX#B21705

RGBrgb(178, 23, 5)

RGB (0–1)0.698, 0.0902, 0.0196

RGB percentages69.8%, 9%, 2%

HSLhsl(6.2, 94.5%, 35.9%)

HSV / HSBhsv(6.2, 97.2%, 69.8%)

CMYK0%, 87.1%, 97.2%, 30.2%≈naive device-independent conversion; real print needs an ICC profile

24-bit integer11,671,301

CSS custom property--colour: #B21705;

Brightness & contrast

Relative luminance0.10089WCAG 2.x, 0 is black and 1 is white

Perceived brightness98.9 of 255ITU-R BT.601 weighting

Light or darkDark

Best text colour on this backgroundWhitecontrast 6.96:1

Contrast with white6.96:1WCAG normal text: AA

Contrast with black3.02:1WCAG normal text: Fail

Greyscale equivalent#373737

Inverted#4DE8FA

Colour vision & accessibility

Normal vision Protanopia Deuteranopia Tritanopia

Protanopia#4E4400no red cones; affects about 1% of men; ΔE 63 from the original

Deuteranopia#736500no green cones; the most common form, about 1% of men; ΔE 62.3 from the original

Tritanopia#C50017no blue cones; rare, and affects men and women equally; ΔE 9.3 from the original

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

Contrast with white, large text6.96:1WCAG large text: AAA

Contrast with black, large text3.02:1WCAG large text: AA

Named colours

Firebrick · ΔE 12.4 Dark red · ΔE 14.8 Maroon · ΔE 19.8 Brown · ΔE 21 Crimson · ΔE 22.6 Tomato · ΔE 24.4

Nearest named CSS colourFirebrick (#B22222)ΔE 12.37, a distinctly different colour

Hue familyred

CSS keyword usableNo exact keyword

Colour harmonies

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

Complementary#05A0B2

Analogous#B20549, #B26E05

Triadic#05B217, #1705B2

Split complementary#05B26E, #0549B2

Tetradic#4AB205, #05A0B2, #6E05B2

Tints, shades & saturation

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

Lighter +40%#FC9387

Lighter +30%#FA6756

Lighter +20%#F93A24

Lighter +10%#E41D06

Darker −10%#801104

Darker −20%#4F0A02

Darker −30%#1D0401

Darker −40%#000000

More saturated +25%#B71300

Less saturated −25%#9B291C

Channel breakdown

R178

G23

Red178 (69.8%)

Green23 (9%)

Blue5 (2%)

Hue6.24°

Saturation (HSL)94.54%

Lightness35.88%

Dominant channelRed

Hex per channelR B2 · G 17 · B 05

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Harmonies

Lighter and darker

Similar named colours

Also reads as

B21705 (chemical formula)

Formula
234,631.05 g/mol
21705 atoms

B21705 has a molar mass of 234,631.05 g/mol, made up of 21705 atoms across 1 element: 21705 × B.

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Molar mass

Molar mass234,631.05 g/mol

Total atoms per molecule21705

Distinct elements1

Mass of one molecule3.8961402 × 10^-19 g

Molecules per gram2.5666427 × 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 × 21705)234,631.05 g/mol, 100%

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Elements in this formula

Boron

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