In Riviera you can observe the evolution, both technical and formal, of the pictorial language ... the stylistic research has taken a high value in the modality and the visual fascinations ... these are now expressed through the masterly play of colour effectst ... the aim of that is also to obtain a greater formal synthesis ... while all that allows him to emphasize the visual pathos of representation. Pierluigi Ercole

It happened that the constant sorrow veil has been thrown to the bottom by the pleasure of existing, by the intense capacity of enjoying things and feelings, which are now spreading without restraint. A condition that naturally takes him to a painting which is getting more and more rarefied, almost spiritual: a reducing process that sometimes hits the limits of the shape dissolution; the emotion that the artist gives us is soft and evasive, and yet it has never been so deep. Lorena Corradini

... ...when painting reaches the expressive intensity of a state of grace where feeling and colour are all the same, every convention, classification is swept away. If the fusion of object, space and atmosphere, peculiar of impressionism, exploits the colour of matter to concentrate the variable vibrations of light and colour and to make them more concrete and less evident, the force of the emotional soul reflection has a true expressionist nature ... images, places are not well identified but they are transfigured into an inner vision that he revives in a dream-like time and surreal light. Arnaldo Maravelli

Sergio Riviera’s painting is intimist, it comes out of overlapped colour coats, suggested more by inner instinctive fine feelings than by a pure technical and intuitive refrain. The pigment is warm, tactile; it seems that colour wants to represent a translation to the tactility of reality to become visual pictorial technique. Mauro Scardua