Comparing Growth Rates Under Different Light Colors

In a recent experiment assessing the effects of different light wavelengths on the growth rate of a specific species of plant, researchers recorded the height of plants exposed to three different light colors—red, blue, and green—over a span of two weeks. The following data was collected:

Red Light:
Day 1: 5 cm
Day 7: 12 cm
Day 14: 18 cm

Blue Light:
Day 1: 4 cm
Day 7: 10 cm
Day 14: 22 cm

Green Light:
Day 1: 6 cm
Day 7: 9 cm
Day 14: 14 cm

Based on this data, which color of light resulted in the highest average growth rate over the entire duration of the experiment?