How RGB to HEX conversion works

Each RGB value (0–255) is converted to a two-digit hexadecimal number. Red 255 → FF, Green 87 → 57, Blue 51 → 33, combined as #FF5733. The formula converts each decimal channel to base-16 and pads single-digit results with a leading zero.

// JavaScript — RGB to HEX
function rgbToHex(r, g, b) {
  return "#" + [r, g, b]
    .map(v => v.toString(16).padStart(2, "0"))
    .join("");
}
rgbToHex(255, 87, 51); // "#ff5733"

# Python
def rgb_to_hex(r, g, b):
    return f"#{r:02x}{g:02x}{b:02x}"
rgb_to_hex(255, 87, 51)  # "#ff5733"

/* CSS — both formats are equivalent */
color: rgb(255, 87, 51);
color: #ff5733;

Shorthand HEX codes

When each hex pair has identical digits (e.g., #AABBCC), the code can be shortened to #ABC. However, #FF5733 cannot be shortened because 57 and 33 have different digits. CSS supports both 3-digit and 6-digit HEX codes. Modern CSS also supports 8-digit hex for alpha transparency: #FF573380 is 50% transparent.