Recognised as Colour

#FF3F31

#FF3F31
Red
Dark
Nearest: Tomato

#FF3F31 is a red with RGB values 255, 63, 49 and HSL 4°, 100%, 60%. It is a dark colour, so black text on it reaches 6:1 contrast (AA for normal text). The nearest named colour is Tomato.

Colour values

#FF3F31#FF3F31

HEX#FF3F31

RGBrgb(255, 63, 49)

RGB (0–1)1, 0.2471, 0.1922

RGB percentages100%, 24.7%, 19.2%

HSLhsl(4.1, 100%, 59.6%)

HSV / HSBhsv(4.1, 80.8%, 100%)

CMYK0%, 75.3%, 80.8%, 0%≈naive device-independent conversion; real print needs an ICC profile

24-bit integer16,727,857

CSS custom property--colour: #FF3F31;

Brightness & contrast

Relative luminance0.25037WCAG 2.x, 0 is black and 1 is white

Perceived brightness148.5 of 255ITU-R BT.601 weighting

Light or darkDark

Best text colour on this backgroundBlackcontrast 6.01:1

Contrast with white3.5:1WCAG normal text: Fail

Contrast with black6.01:1WCAG normal text: AA

Greyscale equivalent#676767

Inverted#00C0CE

Colour vision & accessibility

Normal vision Protanopia Deuteranopia Tritanopia

Protanopia#7B6E2Dno red cones; affects about 1% of men; ΔE 76.1 from the original

Deuteranopia#AA9827no green cones; the most common form, about 1% of men; ΔE 76.3 from the original

Tritanopia#FF003Eno blue cones; rare, and affects men and women equally; ΔE 15.5 from the original

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

Contrast with white, large text3.5:1WCAG large text: AA

Contrast with black, large text6.01:1WCAG large text: AAA

Named colours

Tomato · ΔE 14.8 Orange red · ΔE 16.8 Red · ΔE 18.1 Crimson · ΔE 21.3 Firebrick · ΔE 27.4 Coral · ΔE 27.5

Nearest named CSS colourTomato (#FF6347)ΔE 14.78, a distinctly different colour

Hue familyred

CSS keyword usableNo exact keyword

Colour harmonies

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

Complementary#31F1FF

Analogous#FF318A, #FFA631

Triadic#31FF3F, #3F31FF

Split complementary#31FFA6, #318AFF

Tetradic#8AFF31, #31F1FF, #A631FF

Tints, shades & saturation

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

Lighter +40%#FFFDFD

Lighter +30%#FFCECA

Lighter +20%#FF9E97

Lighter +10%#FF6F64

Darker −10%#FD1100

Darker −20%#CA0E00

Darker −30%#970A00

Darker −40%#640700

More saturated +25%#FF3F31

Less saturated −25%#E5554B

Channel breakdown

R255

G63

B49

Red255 (100%)

Green63 (24.7%)

Blue49 (19.2%)

Hue4.08°

Saturation (HSL)100%

Lightness59.61%

Dominant channelRed

Hex per channelR FF · G 3F · B 31

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Harmonies

Lighter and darker

Similar named colours

Also reads as

FF3F31 (chemical formula)

Formula
664.93 g/mol
35 atoms

FF3F31 has a molar mass of 664.93 g/mol, made up of 35 atoms across 1 element: 35 × F.

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Molar mass

Molar mass664.93 g/mol

Total atoms per molecule35

Distinct elements1

Mass of one molecule1.1041422 × 10^-21 g

Molecules per gram9.0568041 × 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

F100%

Fluorine (F × 35)664.93 g/mol, 100%

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Elements in this formula

Fluorine

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