After the formation of the breakaway FA of Ireland (FAI) and, in 1922, the creation of the Irish Free State, the two rival associations claimed to represent the interests of all Irish clubs and picked players from both north and south of the border for their national sides: some players even played for both associations. The IFA team continued to play as "Ireland" and were recognised by FIFA as the continuation of the former Irish national team.
The IFA along with the other home nations boycotted the FAI until they rejoined FIFA after the Second World War despite several attempts to effect a reconciliation and restore a single body for the whole of Ireland.
Ireland continued to play in their traditional blue and white until 1931, changing to green tops (which were normally worn by the amateur side) or white when playing Scotland. These were also worn in France in February 1928. Players wore their club stockings. They continued to be the weakest of the four home nations, failing to add to their single championship in 1914.
Officially the change from blue to green was made to avoid the regular changes of kit made when Ireland met Scotland but some think the change was motivated by political considerations. The new shamrock crest was almost identical to that worn by the side from the Republic. Players still wore their club stockings until the mid-1930s until standard sets were introduced in navy with a green and white turnover..
: Northern Ireland 1946-1960>