Prismatic Geoscope

Some nonbasic lands do have basic land types. Domain abilities don't count the number of lands you control—they count the number of basic land types among lands you control, even if that means checking the same land twice. For example, if you control a Tundra, a Blood Crypt, and a Forest, you'll have a Plains, Island, Swamp, Mountain, and Forest among the lands you control. Your domain abilities will be maxed out.

Most nonbasic lands don't have basic land types, even if they produce colored mana. For example, Caves of Koilos is neither a Plains nor a Swamp.

Prismatic Geoscope can't produce colorless mana.