Question

Why is the colour of a leaf kept in the dark frequently yellow or pale green?

Answer 1

Answer:

The plants which are kept in the dark are generally yellow, or pale green because the production of the chlorophyll pigment (essential for photosynthesis) is directly proportional to the amount of light available. ... This changes the color of the leaf gradually to light green.

hope it helps you too

Answer 2

Answer:

Chlorophyll fails to absorb the energy in the absence of light; hence it loses stability to give the leaf yellow colouration. This proves that carotenoids which imparts yellow color is more stable.