Petri dishes with cetrimide agar. Pseudomonas aeruginosa growing on cetrimide agar. Cultivation 24 hours at 37°C.

Pseudomonas aeruginosa produces a number of water-soluble pigments. When the yellow-green pyoverdine combines
with the blue water-soluble pigment pyocyanin, the bright green color characteristic of Pseudomonas aeruginosa is created.