Final answer:
The colors in the Grand Prismatic Spring are produced by photosynthetic bacteria called cyanobacteria, which selectively capture and reflect sunlight. The bacteria use light energy for photosynthesis.
Step-by-step explanation:
The array of vivid colors within Grand Prismatic Spring is produced by photosynthetic bacteria called cyanobacteria. These bacteria capture some wavelengths of sunlight and reflect others, resulting in the different colors seen around the edges of the spring. The colors are a result of the bacteria's use of light energy for photosynthesis.