Recognised as Colour

#FF1737

#FF1737
Red
Dark
Nearest: Crimson

#FF1737 is a red with RGB values 255, 23, 55 and HSL 352°, 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

#FF1737#FF1737

HEX#FF1737

RGBrgb(255, 23, 55)

RGB (0–1)1, 0.0902, 0.2157

RGB percentages100%, 9%, 21.6%

HSLhsl(351.7, 100%, 54.5%)

HSV / HSBhsv(351.7, 91%, 100%)

CMYK0%, 91%, 78.4%, 0%≈naive device-independent conversion; real print needs an ICC profile

24-bit integer16,717,623

CSS custom property--colour: #FF1737;

Brightness & contrast

Relative luminance0.22149WCAG 2.x, 0 is black and 1 is white

Perceived brightness141.8 of 255ITU-R BT.601 weighting

Light or darkDark

Best text colour on this backgroundBlackcontrast 5.43:1

Contrast with white3.87:1WCAG normal text: Fail

Contrast with black5.43:1WCAG normal text: AA

Greyscale equivalent#4B4B4B

Inverted#00E8C8

Colour vision & accessibility

Normal vision Protanopia Deuteranopia Tritanopia

Protanopia#6D6335no red cones; affects about 1% of men; ΔE 85 from the original

Deuteranopia#A3922Cno green cones; the most common form, about 1% of men; ΔE 84.8 from the original

Tritanopia#FF0029no blue cones; rare, and affects men and women equally; ΔE 6.8 from the original

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

Contrast with white, large text3.87:1WCAG large text: AA

Contrast with black, large text5.43:1WCAG large text: AAA

Named colours

Crimson · ΔE 16.7 Red · ΔE 20.9 Tomato · ΔE 22.6 Orange red · ΔE 25.5 Firebrick · ΔE 28.9 Coral · ΔE 36.1

Nearest named CSS colourCrimson (#DC143C)ΔE 16.71, a distinctly different colour

Hue familyred

CSS keyword usableNo exact keyword

Colour harmonies

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

Complementary#17FFDF

Analogous#FF17AB, #FF6B17

Triadic#37FF17, #1737FF

Split complementary#17FF6B, #17ABFF

Tetradic#ABFF17, #17FFDF, #6B17FF

Tints, shades & saturation

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

Lighter +40%#FFE3E7

Lighter +30%#FFB0BB

Lighter +20%#FF7D8F

Lighter +10%#FF4A63

Darker −10%#E3001F

Darker −20%#B00018

Darker −30%#7D0011

Darker −40%#4A000A

More saturated +25%#FF1737

Less saturated −25%#E2344C

Channel breakdown

R255

G23

B55

Red255 (100%)

Green23 (9%)

Blue55 (21.6%)

Hue351.72°

Saturation (HSL)100%

Lightness54.51%

Dominant channelRed

Hex per channelR FF · G 17 · B 37

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Harmonies

Lighter and darker

Similar named colours

Also reads as

FF1737 (chemical formula)

Formula
33,018.524 g/mol
1738 atoms

FF1737 has a molar mass of 33,018.524 g/mol, made up of 1738 atoms across 1 element: 1738 × F.

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Molar mass

Molar mass33,018.524 g/mol

Total atoms per molecule1738

Distinct elements1

Mass of one molecule5.4828549 × 10^-20 g

Molecules per gram1.8238673 × 10^19

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 × 1738)33,018.524 g/mol, 100%

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Elements in this formula

Fluorine

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