man it is not the color ..which matters the colour depends on the indicator.. in the pH scale O is very acidic and 14 is very basic.7 is neutral. pH do not depend on colour.absolutely no relation.........eg : neurotic acid with pH zero is plain like water. Here is another attempt to answer your question: http://en.wikipedia.org/wiki/Universal_i...
Acrylic Adhesives. Acrylic adhesives can either be water-based (this is also referred to as emulsion or dispersion) or solvent-based. Water-based are slower drying compared to solvent-based systems but generally solvent-based acrylic systems have better resistance to other solvents, chemicals and water.
The glue cleans up with soap and water. Tacky glue is not pH neutral and should not be used for archiving items. This and other types of PVA glues must be kept from freezing. The most popular brands for this type of glue are Aleene's, Elmer's, Scotch Quick Drying and Acme.