The flag of Gibraltar consists of a white background with a red castle and a gold key in the center. The castle has three towers, one on each side, and a central gateway with a pointed arch. The key is located above the castle and has a black handle and a silver tip. The aspect ratio is 1:2 (height to width). The geometric properties are that the castle is centered vertically and horizontally, and the key is centered vertically above the castle. The color codes for the flag are as follows:

• White: #FFFFFF
• Red: #CE1126
• Gold: #FFC20E
• Black: #000000
• Silver: #C0C0C0

There are no specified measurements for the flag's elements.