The flag of Japan, known as the Nisshōki or Hinomaru, features a red circle on a white background. The color codes are:

• Red: #BC3F4A
• White: #FFFFFF

The flag has an aspect ratio of 2:3. The red circle, representing the sun, is positioned at the center of the flag and has a diameter equal to 3/5 of the flag's height. The distance from the circle's center to the hoist (left) edge is equal to the distance from the top edge to the circle's center, which is 1/2 of the flag's height.

In summary:

• Aspect ratio: 2:3
• Red circle diameter: 3/5 of the flag's height
• Circle's center position: Equidistant from the hoist and top edges (1/2 of the flag's height)