I find I have a number white photos both of birds and flowers. Starting with Great Egret resting in a tree.
Another white bird is the trunda swan swimming with other ducks. This was taken at Pahranagat National Wildlife Refuge North Marsh. It was a sight to watch over a hundred off these birds rises up and return to the water
The Plant Kingdom has many white flowers Here are roses.
White daisies like a sunny dry location and will naturalize for you.