The pigment present universally in all green oxygenic plants is

The pigment present universally in all green oxygenic plants is Chlorophyll a.
Chlorophyll a is a specific form of chlorophyll used in oxygenic photosynthesis. It absorbs most energy from wavelengths of violet-blue and orange-red light, and it is a poor absorber of green and near-green portions of the spectrum, thus reflecting green colour makes the plant look green.
Chlorophyll a is very important in the energy phase of photosynthesis.