Light sources for illumination of liquids in a variety of environments. In one example, multi-color LED-based light sources are adapted to engage mechanically and electrically with various types of conventional light sockets, including light sockets conventionally found in a pool or spa environment. In another example, a light fixture for a pool or spa is particularly adapted to engage mechanically and electrically with a wedge type socket supported by a pool or spa. In another example, a light fixture for illumination of liquids includes an encapsulant to protect the light fixture from moisture, due to the characteristically humid environment encountered in liquid illumination applications.