The Correlation. Correlation is a measue of how close the line fits the points that you found in your experiment. Anyone can say whether they think the line is a good fit or not, but to measure it exactly, we use the correlation coefficient: R2.
As the seasons change and the amount of sunlight decreases, less chlorophyll is produced, and the leaves appear less green. Chlorophyll is broken down into simpler compounds at a constant rate, so green leaf color will gradually fade as chlorophyll production slows or stops.
Answer 2: The color or wavelength of light does affect photosynthesis, which is how plants can basically create their own food.Essentially, the reason why plants are green is they are absorbing the other wavelengths of light but reflecting back the green. The wikipedia page on photosynthesis goes into a lot more detail.