How does the light color affect photosynthesis?

Phototropism is the tendency of plants to move toward a light source.

for instance, plant an avocado seed and watch how the stem and leaves will turn toward the brightest light. If you leave it stationary, do not turn it, the plant will begin to bow in that direction.

The color of light may have little actual affect on most plants, however some plants that are more suited for darker environments may move more slowly to some lights and more quickly to others.