The flag of Brunei has a base of yellow, with two diagonal black and white stripes, and a red crest emblem in the center. The aspect ratio is 1:2.

Color codes:

• Yellow: Pantone 116 C, HEX #FFCD00
• White: HEX #FFFFFF
• Black: HEX #000000
• Red: Pantone 186 C, HEX #C8102E

The flag's design:

1. Base: A yellow field that occupies the entire background.
2. Stripes: Two diagonal stripes, one black and one white, originating from the lower hoist corner (bottom-left) extending to the upper fly corner (top-right). The black stripe is on top of the white stripe and both are equally wide.
3. Emblem: A red crest (Brunei's national emblem) centered on the flag, overlapping the two diagonal stripes.

Geometric properties and measurements:

• The width of each diagonal stripe is approximately 1/8 of the flag's height.
• The red crest's height is about half the flag's height and its width is proportionate to the design.

These elements combine to form the flag of Brunei without considering the symbolism behind them.