In desi weddings, its ok for guests to wear red. Infact the more dressed up you are the more close to the bride you are. Most of you have been born in the West so the cue not to wear the color the bride is wearing comes from there. When my SIl got married, my MIl was mad that I wasn’t wearing my wedding dress on that occasion. Obviously she wouldn’t want me to upstage her own daughter, right?