Is colour change a good measure of water penetration in cement?

Further information

PhD thesis Noemi Fischer , Validation of conventional concrete water transport test methods by spatially resolved 1H magnetic resonance [PDF]

N Fischer, R. Haerdtl, P. J. McDonald, Observation of the redistribution of nanoscale water filled porosity in cement based materials during wetting, Cement and Concrete Research, Volume 68, February 2015, Pages 148–155 [PDF]
DOI: 10.1016/j.cemconres.2014.10.013