In Croatia, Kolossa families are Croats (from Zagreb ). In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb.
Prevalence
Only a few people with faimily name Kolossa live in Croatia today, in one household only. There were 0 of them in the middle of the past century, and their number remains constant. They are located in one Croatian city only, in Zagreb (<5).
Outside Croatia
Family name Kolossa is present in 16 countries worldwide.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1929 in source Emigration Commission Zagreb.