What happens in respiration that causes colour change?

In respiration, particularly during cellular respiration, the metabolic processes involve the oxidation of glucose, leading to the production of carbon dioxide and water. This process can result in color changes in certain organisms or environments due to the presence of pigments that respond to changes in pH or oxidation states. For example, in some aquatic plants and algae, the accumulation of carbon dioxide can lower pH, affecting pigment structures and leading to visible color changes. Additionally, the activity of respiring organisms can influence the coloration of their surroundings, such as the reddening of certain tissues in plants under stress.