This investigation involves the catalytic transformations of phenethyl alcohols over gamma-alumina (from aluminiumisopropoxide, aluminium foil, aluminium nitrate, aluminium sulphate), gamma-alumina modified by 0.5% hydrofluoric acid and sodium, potassium, magnesium, calcium (1.0% each), alpha-alumina, silica from tetraethyl orthosilicate and sodium meta silicate, titania, chromia, zinc oxide, calcium oxide, magnesium oxide, silica-alumina of varying silica-alumina ratios (0.88, 1.86, 3.96), chromia-alumina, 5.0% vanadia-titania, 0.5% tin-silica, 0.3% platinum-alumina, 1.0% copper-zinc oxide, 1.0% copper-silica, copper aluminate, copper chromite, nickel aluminate, nickel chromite, zinc ferrite, H ZSM-5 (80), Na ZSM-5 (80) acid 2.0% Ga H ZSM-5 (80) zeolite catalysts in a vertical flow quartz reactor in the temperature range of 325-450 degrees C and at a contact time of 1.96 h. The reaction products consist of styrene, acetophenone, dibenzyl methyl ether, methyl phenyl indan from 1-phenyl ethanol and styrene, phenyl acetaldehyde, phenyl acetic acid, methyl phenyl indan, diphenethyl ether, phenyl acetate, styrene oxide, ethylbenzene, toluene, benzene, 1,3-diphenyl butane, 1,3-diphenyl butene from 2-phenyl ethanol. Selective conversion of phenethyl alcohols to styrene is achieved over fluorided alumina and gamma-alumina from aluminiumisopropoxide. The catalysates obtained from 1-phenyl ethanol over all catalysts are colourless, whereas that from 2-phenyl ethanol over copper aluminate, alpha-alumina, chromia, Ga H ZSM-5(80) etc., are coloured. The notable difference in the composition of the products from 2-phenyl ethanol and 1-phenyl ethanol are the additional presence of phenyl acetaldehyde and phenyl acetic acid in the former, which are the source for proton. The styryl cation radical formation, established by ESR was considered to be responsible for colour formation and the spin concentrations were calculated for coloured samples. The formation of cationic species was further analyzed by UV absorption spectra. The colour intensity is maximum when the weight ratio of styrene to phenyl acetaldehyde plus phenylacetic acid is less than unity.