It’s normal these days for the top clubs to have 3 different jerseys in a season. The usual home and away jerseys have been common for a long time and in recent years, the 3rd kit has been introduced but used very rarely.
The above jersey is reportedly set to be Barcelona’s 4th jersey next season. It features 4 stripes that represent the bloody fingers on Guifre el Pilos, considered the founder of Catalonia, and the colors are of the Catalonia flag.
Barca’s home jersey next season is reportedly going to be similar to Croatia’s World Cup kit. Meanwhile, their away jersey will be yellow and the 3rd kit will be green according to the same report.