Brunei uses a National Registration Identity Card system, which is issued to all citizens aged 12 and over. All citizens are issued with a unique NRIC Identity Card number.
Brunei issues three (3) types of national smart identity cards (SIC):
Smart Identity Card (Yellow) - Citizens of Brunei Darussalam
Smart Identity Card (Purple) - Permanent Residents of Brunei Darussalam
Smart Identity Card (Green) - Foreigners staying in the country for a period of more than 3 months.
You can get more info here: https://www.brunei.gov.bn