Euglenophyta are unique among algae because they possess both chlorophyll a and b, similar to green plants, along with various carotenoids. This pigment composition is a key diagnostic feature used in the classification of Euglenoids, which are often found in freshwater habitats.

Cyanobacteria store their excess photosynthetic products primarily as cyanophycean starch, which is structurally similar to glycogen. This storage polysaccharide is deposited in the cytoplasm as granules. The ability to store energy in this form allows cyanobacteria to survive periods of darkness or nutrient limitation, ensuring metabolic continuity when external resources are scarce.

Lutein is a widespread xanthophyll pigment found across many algal groups, including Chlorophyta. While fucoxanthin is dominant in Phaeophyta and myxoxanthin in Cyanophyta, lutein is generally considered one of the most ubiquitous xanthophylls in the algal kingdom.

Bacillariophytes, commonly known as diatoms, possess plastids that contain chlorophylls a and c, along with accessory pigments like fucoxanthin. The presence of these carotenoids, particularly fucoxanthin, gives the plastids a distinct golden-brown or brownish appearance.

In Cyanobacteria, photosynthetic pigments such as chlorophyll a and accessory pigments are embedded within specialized internal membrane structures called thylakoids. These membranes are arranged in parallel or concentric layers within the cytoplasm. Phycobilins are specific accessory pigments associated with these thylakoids, organized into structures called phycobilisomes, which help capture light energy for the photosynthetic process.

Phycoerythrin is a red-colored phycobiliprotein pigment found primarily in Rhodophyta (red algae) and some cyanobacteria. It functions as an accessory light-harvesting pigment, absorbing blue and green light wavelengths, which allows these organisms to perform photosynthesis at greater depths in the water column where other light wavelengths are filtered out.

Phycobilins are water-soluble accessory pigments found in cyanobacteria, red algae, and glaucophytes. These pigments, which include phycocyanin and phycoerythrin, are organized into structures called phycobilisomes on the surface of thylakoid membranes. They capture light energy in the green-yellow part of the spectrum, which chlorophyll a cannot efficiently absorb, thereby enhancing photosynthetic efficiency.

Rhodophyta (red algae) are unique among eukaryotic algae because they possess chlorophyll a and chlorophyll d. While chlorophyll a is universal to all oxygenic photosynthetic organisms, the presence of chlorophyll d is a diagnostic feature for many red algae, allowing them to absorb light in the far-red region of the spectrum, which is beneficial in deep-water habitats.

Xanthophylls are oxygenated carotenoid pigments that generally exhibit colors ranging from yellow to brownish-yellow. They play a crucial role in photosynthesis by expanding the range of light absorption and protecting the photosynthetic apparatus from photo-oxidative damage by dissipating excess energy as heat.

Phaeophyta, commonly known as brown algae, derive their characteristic color from the presence of the accessory pigment fucoxanthin, which masks the green chlorophyll a and c. This pigment allows them to absorb light efficiently in deeper marine environments, distinguishing them from green or red algae.