In this video you will see 180 priests in white cassocks/habits. Though some are Dominicans, the majority are not. Neither are they Nobertines. The procession of priests you will see in the video are from the Carmelites, Redemptorists, Diocesan, etc… Because they are living in Singapore, a tropical country, their cassocks/habits are made of white fabric.
Bishops have purple lining and purple fascia while priests may choose to use black piping and wear the black fascia- though it’s extremerly rare.
Ps. The video is actually a clip of a funeral procession of the late Abp. Emeritus of the Archdiocese of Singapore.