Recognised as Colour

#FF173B

#FF173B
Red
Dark
Nearest: Crimson

#FF173B is a red with RGB values 255, 23, 59 and HSL 351°, 100%, 55%. It is a dark colour, so black text on it reaches 5.4:1 contrast (AA for normal text). The nearest named colour is Crimson.

Colour values

#FF173B#FF173B

HEX#FF173B

RGBrgb(255, 23, 59)

RGB (0–1)1, 0.0902, 0.2314

RGB percentages100%, 9%, 23.1%

HSLhsl(350.7, 100%, 54.5%)

HSV / HSBhsv(350.7, 91%, 100%)

CMYK0%, 91%, 76.9%, 0%≈naive device-independent conversion; real print needs an ICC profile

24-bit integer16,717,627

CSS custom property--colour: #FF173B;

Brightness & contrast

Relative luminance0.22189WCAG 2.x, 0 is black and 1 is white

Perceived brightness142 of 255ITU-R BT.601 weighting

Light or darkDark

Best text colour on this backgroundBlackcontrast 5.44:1

Contrast with white3.86:1WCAG normal text: Fail

Contrast with black5.44:1WCAG normal text: AA

Greyscale equivalent#4B4B4B

Inverted#00E8C4

Colour vision & accessibility

Normal vision Protanopia Deuteranopia Tritanopia

Protanopia#6D633Ano red cones; affects about 1% of men; ΔE 84.7 from the original

Deuteranopia#A39231no green cones; the most common form, about 1% of men; ΔE 84.6 from the original

Tritanopia#FF002Bno blue cones; rare, and affects men and women equally; ΔE 8 from the original

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

Contrast with white, large text3.86:1WCAG large text: AA

Contrast with black, large text5.44:1WCAG large text: AAA

Named colours

Crimson · ΔE 15.2 Tomato · ΔE 22.8 Red · ΔE 23.1 Orange red · ΔE 27.5 Firebrick · ΔE 28.5 Coral · ΔE 36.4

Nearest named CSS colourCrimson (#DC143C)ΔE 15.21, a distinctly different colour

Hue familyred

CSS keyword usableNo exact keyword

Colour harmonies

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

Complementary#17FFDB

Analogous#FF17AF, #FF6717

Triadic#3BFF17, #173BFF

Split complementary#17FF67, #17AFFF

Tetradic#AFFF17, #17FFDB, #6717FF

Tints, shades & saturation

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

Lighter +40%#FFE3E7

Lighter +30%#FFB0BC

Lighter +20%#FF7D91

Lighter +10%#FF4A66

Darker −10%#E30023

Darker −20%#B0001B

Darker −30%#7D0013

Darker −40%#4A000B

More saturated +25%#FF173B

Less saturated −25%#E2344F

Channel breakdown

R255

G23

B59

Red255 (100%)

Green23 (9%)

Blue59 (23.1%)

Hue350.69°

Saturation (HSL)100%

Lightness54.51%

Dominant channelRed

Hex per channelR FF · G 17 · B 3B

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Harmonies

Lighter and darker

Similar named colours

Also reads as

FF173B (chemical formula)

Formula
3,316.462 g/mol
175 atoms

FF173B has a molar mass of 3,316.462 g/mol, made up of 175 atoms across 2 elements: 174 × F, 1 × B.

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Molar mass

Molar mass3,316.462 g/mol

Total atoms per molecule175

Distinct elements2

Mass of one molecule5.5071147 × 10^-21 g

Molecules per gram1.8158329 × 10^20

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

F99.7%

B0.3%

Fluorine (F × 174)3,305.652 g/mol, 99.674%

Boron (B)10.81 g/mol, 0.326%

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