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💡 Click on any color value below to copy it to clipboard
Running Number
15,932,187
HEX
#F31B1B
RGB
243, 27, 27
HSL
0°,90%,53%
HSV
0°,89%,95%
CMYK
0%,89%,89%,5%
Brightness
36%
Type
Dark
AA Normal Text: ≥ 4.5:1
AA Large Text: ≥ 3.0:1
AAA Normal Text: ≥ 7.0:1
AAA Large Text: ≥ 4.5:1
#F31B1B sits at 0° on the color wheel, placing it in the red family of the warm half of the spectrum. With 90% saturation and 53% lightness, it reads as a fully saturated, balanced tone — an immediate, signal-grade voice that demands attention. Its RGB mix of 243, 27, 27 produces a 4.98:1 contrast ratio against black, which clears WCAG AA for body text in that pairing.
In RGB space #F31B1B is a clear variant of CSS red — about 40 units away from #FF0000. Designers reach for red hues at this saturation when the brief calls for bold, immediate signal, and at this lightness when they want a present, comfortable mid-canvas voice. On screen the warm cast tends to pair best with cool neutrals around 210°-230° to balance temperature.
See how this color appears in real UI elements
Button (filled)
Badge
Progress Bar
Link Hover
Input Focus Ring
Checkbox Active
Toggle Switch On
Slider Thumb
Card Border
Icon Highlight
Tooltip Background
Modal Header
Tab Active
Alert Box
Timeline Dot
Loading Spinner
Dropdown Selected
Table Row Highlight
Calendar Date
Mobile Device
See how to use #F31B1B in different programming languages
| Platform | Languages |
|---|---|
| Frontend | |
| Mobile | |
| Backend | |
| Others |
document.getElementById("box").style.backgroundColor = "#f31b1b";💡 Click any tab to see how to use #f31b1b in different programming languages