The flag of Brunei has a centered crest of Brunei on a yellow field cut by black and white diagonal stripes (parallelograms at an angle). The yellow field represents the sultan of Brunei. The red crest consists of a crescent facing upwards, joined with a parasol, with hands-on the sides. Black and white stripes run across the flag.

In Southeast Asia, yellow is traditionally the color of royalty, and the royal standards of Malaysia and Thailand, and the flag of Sarawak, along with the presidential flag of Indonesia, all use a yellow field as well.

The crescent symbolizes Islam, the parasol symbolizes monarchy, and the hands at the side symbolize the benevolence of the government. The black and white stripes represent Brunei's chief ministers who were once joint-regents and then – after the sultan came of age – senior advisors: the Pengiran Bendahara (First Minister, symbolised by a slightly thicker white stripe) and the Pengiran Pemancha (Second Minister, governing foreign affairs, symbolised by black), with the white stripe being roughly 12% wider than the black one.

More Info: en.wikipedia.org