Recognised as Colour
#FF581F
- #FF581F
- Orange
- Dark
- Nearest: Orange red
#FF581F is a orange with RGB values 255, 88, 31 and HSL 15°, 100%, 56%. It is a dark colour, so black text on it reaches 6.7:1 contrast (AA for normal text). The nearest named colour is Orange red.
Colour values
#FF581F#FF581F
HEX#FF581F
RGBrgb(255, 88, 31)
RGB (0–1)1, 0.3451, 0.1216
RGB percentages100%, 34.5%, 12.2%
HSLhsl(15.3, 100%, 56.1%)
HSV / HSBhsv(15.3, 87.8%, 100%)
CMYK0%, 65.5%, 87.8%, 0%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer16,734,239
CSS custom property--colour: #FF581F;
Brightness & contrast
Relative luminance0.28338WCAG 2.x, 0 is black and 1 is white
Perceived brightness155.2 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundBlackcontrast 6.67:1
Contrast with white3.15:1WCAG normal text: Fail
Contrast with black6.67:1WCAG normal text: AA
Greyscale equivalent#777777
Inverted#00A7E0
Colour vision & accessibility
Distinguishable without hueShifts in lightness toonever rely on hue alone to carry meaning
Contrast with white, large text3.15:1WCAG large text: AA
Contrast with black, large text6.67:1WCAG large text: AAA
Named colours
Hue familyorange
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#1FC6FF
Analogous#FF1F56, #FFC81F
Triadic#1FFF58, #581FFF
Split complementary#1FFFC8, #1F56FF
Tetradic#56FF1F, #1FC6FF, #C81FFF
Tints, shades & saturation
Channel breakdown
R255
G88
B31
Red255 (100%)
Green88 (34.5%)
Blue31 (12.2%)
Hue15.27°
Saturation (HSL)100%
Lightness56.08%
Dominant channelRed
Hex per channelR FF · G 58 · B 1F
Keep nerding
Every link below is a page Nerdulator can generate from what it already knows about this value.
Also reads as
FF581F (chemical formula)
- Formula
- 11,075.834 g/mol
- 583 atoms
FF581F has a molar mass of 11,075.834 g/mol, made up of 583 atoms across 1 element: 583 × F.
Molar mass
Molar mass11,075.834 g/mol
Total atoms per molecule583
Distinct elements1
Mass of one molecule1.8391855 × 10^-20 g
Molecules per gram5.4371894 × 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 × 583)11,075.834 g/mol, 100%
Keep nerding
Every link below is a page Nerdulator can generate from what it already knows about this value.
Elements in this formula
Nerdulate something else
Nothing in mind? Surprise me · today’s page