Pigments absorb certain wavelengths of light and reflect others.
Most photosynthetic pigments are not soluble in water and therefore can only be eluted using non-polar solvents.
Chlorophyll, for example, can be found in all photosynthesizing plants and algae. It absorbs light between 400-500 nm and 600-700 nm, depending on the structural groups attached to the porphyrin ring. As you can easily guess from its structure below, chlorophyll is hydrophobic.