The flag of Hong Kong features a red field with a white, stylized, five-petal Bauhinia blakeana flower in the center. The aspect ratio of the flag is 1:2.

Colors:

• Red: Pantone 186 C, HEX #E2231A
• White: Pantone Safe, HEX #FFFFFF

Geometric properties and measurements:

• The diameter of the flower is equal to 0.6 times the hoist width.
• Each petal contains a red five-pointed star with a red double-line border. The stars have a diameter equal to 0.1 times the hoist width.
• The distance between the center of the flower and the midpoint of each petal's outer edge is equal to 0.5 times the hoist width.
• The angle between two adjacent petals is 72 degrees.

These are the main geometric properties and color codes for the flag of Hong Kong.