Not on the same plant but the two can produce pink with cross pollination between the two.

If it appears to be on the same plant, it may be two separate seedlings closely intertwined, or it could be what is called a bud sport--a genetic mutation that occurred in the growing point of one of the branches of the plant, changing the white flower cells to pink. Occasionally, that will also produce flowers that are pink on the right, and white on the left, or vice versa, or striped....

Never thought of that Tug. There are thousands of wild pink ones round here but no white. Its certainly very pretty. Do you suppose there would be any chance of a cutting rooting?

This looks like the lychnis coronaria which seeds itself around my garden, cerise, pale pink, white and white with a pink centre exactly like your photo.

Good point Pennyfarthing- you could be right there

I think it is Lychnis oculata.

L. oculata is usually listed as a subspecies or color form of L. coronaria, so both Scotsgran and Pennyfarthing could be right.

See this link.
https://www.plantsofdistinction.co.uk
It says "A silver leaved Lychnis with pure white flowers slowly changing to pink as they age Not an illusion but seems like it. 24-30".
This link https://www.plant-world-seeds.com/store/view_seed_item/876
gives more information on the colour /changes.

That's interesting, Scotsgran. That hasn't happened with mine--they remain the same colour throughout. They do have silver foliage though. I've not come across L. oculata at all but will look out for it.

I have only seen the ones grown from seed by my friend. It is a perennial.