From The Document Foundation Wiki
Select the area to be formatted. After selection of a range, the first cell selected remains the current cell.
Sélection de A1:A5
Go to ▸ ▸
Check Condition 1 and select Formula is.
- In the adjacent area, type the formula :
STYLE(SI(A1=1;"green";SI(A1=2;"yellow";SI(A1=3;"orange";SI(A1=4;"red";"Default")))))