Water purified for drinking purposes is simply called ndm deum (drinking water), whether it is boiled or filtered. All water offered to customers in restaurants or hotels will be purified, so don't fret about the safety of taking a sip. In restaurants you can ask for ndm pao (plain water, which is always either boiled or taken from a purified source) served by the glass at no charge, or order plain or carbonated water by the bottle. In remote villages you'll often be served water with a distinct colour - usually yellow or red -and a smoky taste. This water is safe to drink and the colour comes from a root which is boiled with the water, the specific root differing depending on where you are.