Recognised as Colour
#CA251B
- #CA251B
- Red
- Dark
- Nearest: Firebrick
#CA251B is a red with RGB values 202, 37, 27 and HSL 3°, 76%, 45%. It is a dark colour, so white text on it reaches 5.5:1 contrast (AA for normal text). The nearest named colour is Firebrick.
Colour values
#CA251B#CA251B
HEX#CA251B
RGBrgb(202, 37, 27)
RGB (0–1)0.7922, 0.1451, 0.1059
RGB percentages79.2%, 14.5%, 10.6%
HSLhsl(3.4, 76.4%, 44.9%)
HSV / HSBhsv(3.4, 86.6%, 79.2%)
CMYK0%, 81.7%, 86.6%, 20.8%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer13,247,771
CSS custom property--colour: #CA251B;
Brightness & contrast
Relative luminance0.13959WCAG 2.x, 0 is black and 1 is white
Perceived brightness114.4 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundWhitecontrast 5.54:1
Contrast with white5.54:1WCAG normal text: AA
Contrast with black3.79:1WCAG normal text: Fail
Greyscale equivalent#474747
Inverted#35DAE4
Colour vision & accessibility
Distinguishable without hueShifts in lightness toonever rely on hue alone to carry meaning
Contrast with white, large text5.54:1WCAG large text: AAA
Contrast with black, large text3.79:1WCAG large text: AA
Named colours
Hue familyred
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#1BC0CA
Analogous#CA1B68, #CA7D1B
Triadic#1BCA25, #251BCA
Split complementary#1BCA7D, #1B68CA
Tetradic#68CA1B, #1BC0CA, #7D1BCA
Tints, shades & saturation
Channel breakdown
R202
G37
B27
Red202 (79.2%)
Green37 (14.5%)
Blue27 (10.6%)
Hue3.43°
Saturation (HSL)76.42%
Lightness44.9%
Dominant channelRed
Hex per channelR CA · G 25 · B 1B
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Also reads as
Ca251B (chemical formula)
- Formula
- 10,070.388 g/mol
- 252 atoms
Ca251B has a molar mass of 10,070.388 g/mol, made up of 252 atoms across 2 elements: 251 × Ca, 1 × B.
Molar mass
Molar mass10,070.388 g/mol
Total atoms per molecule252
Distinct elements2
Mass of one molecule1.6722273 × 10^-20 g
Molecules per gram5.9800484 × 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
Ca99.9%
B0.1%
Calcium (Ca × 251)10,059.578 g/mol, 99.893%
Boron (B)10.81 g/mol, 0.107%
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