The authors agree that the surname derives from Còla, a reduced form of the name Nicola or Nicolo obtained by suppression of the initial syllable. E. De Felice notes that this base was frequent especially in southern Italy, in the northeast —in the regions of Veneto, Friuli-Venezia Giulia and Trentino-Alto Adige— and in part of the central Adriatic areas, favoured by the Greek-Eastern tradition and the cult of Saint Nicholas of Bari.

De Felice adds that the type Colaci, with the suffix -aci from the Greek -ákion, is specific to the areas of the grika language of the far southern peninsula, while the forms in Cu- are Sicilian. Among the areas of high frequency he mentions Tuscany for Coli, and the Italian northeast for Coletti, Colussi, Colaussi, Colotti, Colosi and Colautti.

E. Rossoni specifies the geographical distribution of the main variants: Cola appears in the central strip of Lazio, the Marche and lower Romagna, with specific areas also in the Naples area and in the centre-north of Italy. Coli is very widespread in Emilia —especially in the Reggio area—, in Tuscany —Florence and Pisa areas—, and in the Pesaro, Perugia, Viterbo and Rome areas. The variant Colo is of very scarce presence.