The picture explains the peptide titanyl phthalocyanine, and the distinction mentioned in the title is a bit overwhelming. The answer is for reference:

① Titanium (Ti) is a silver-gray metal, and three substances can be distinguished by naked eyes;

(2) Peptide and phthalein are two organic compounds. It is necessary to indicate which kind of peptide and phthalein are, so as to determine how to distinguish them.