While coloring these materials in reddish, yellow, dark gray, brown, orange and even green tones is economical and stability is assured, in the case of coloring in blue, economic problems arise due to the high price or deshading due to lack of color. chemical stability of the pigment.

Only cobalt blues provide full stability, but their prohibitive price greatly limits their use.

Under certain conditions, other considerably cheaper alternative pigments are used, but they are not free of risks due to the possibility of color degradation. These pigments susceptible to “failure” are ultramarine blues, with a characteristic reddish hue, and Phthalocyanine blues, whose coloring strength is very high. It will therefore be very important to demand from the supplier all the information to weigh the risks, and always do prior tests on the specific application. In any case no one can give a guarantee of success when they are used. Only the promoter should be the one who assumes responsibility in return for obtaining a relatively inexpensive blue pigmentation compared to having used cobalt blue.

The point is that cobalt blue is suitable for all applications, cement, plastic, paint, ceramics, etc., while ultramarine blue has as its main application plastic and Phthalocyanine paints and plastics.

As a summary, a developer desiring blue-colored cementitious products should be informed of the options.