@royal Yep!
White top is common. For bottom, there isn't exactly any preference, shorts are fine even. ^_~
Some families also announce what to wear for burial day. If a family want it to be formal, it's when they inform everyone to come in semi-formal attire on top of wearing white tops. However, most Filipino families are fine with any bottoms as long as it's white tops.
Even footwear, if you want to come in slippers, that's fine too. ^_^
In case you were already outside when you heard, like coming from the office, whatever you're wearing is fine. We generally explain when we arrive; or the grieving family immediately asks, “you came from work? Thank you for coming, it's probably out of your way.”