Just like in the original MONOPOLY, each Property Tile belongs to a Color Set.
Outfit every Property Tile within a single Color Set with Hotels and those Tiles will begin to glow.
The next time you land on any Tile in that Color Set, you will get a chance to spin the Color Set Wheel.
After you spin the wheel for a reward, you'll earn one Net Worth point for each Property Tile in the set and the Hotels will be removed.