The photosynthetic pigments' hydrophobic characteristic assists them to stay within the chloroplast. It is because the pigments like chlorophyll comprise a fat-soluble hydrophobic phytol chain that permits them to get entrenched within the chloroplast's lipid membrane.
On the other hand, the remaining part of the pigment's structure is found in the external composition of the membrane. Therefore, it makes the site within the chloroplast permeable.