Pelamin (wedding dais) is specially for "bersanding" ceremony -- the highlight  event besides the akad nikah (marriage contract).

Grandly designed and gaily decorated, to create some symbolism of a king and queen sitting in state.

On the wedding day, Malays call the bride and groom  as "Raja Sehari" or "Royals for the day". They are therefore treated as such on that day. And royal colors like yellow and tints of yellow are appropriately used during weddings to bring out the ambiance.