Aerogels by them selves are hydrophilic, and if they soak up dampness they typically go through a structural improve, like contraction, and deteriorate, but degradation could be prevented by producing them hydrophobic, by way of a chemical treatment method. The slight colour it does have is due to Rayleigh scattering https://devinggfda.laowaiblog.com/32633907/facts-about-polycarboxylate-superplasticizer-revealed