What flower is this

I love taking photos of flowers. Everyday when l am out on my walk l always find something to photograph. I may love these flowers but l don't know what most of them are.
This one is a firm favourite.

These are perfectly formed little buds of pink and white. The bush is what l would call medium sized with dark green leaves.
It also comes in red and yellow.

I think l like these ones even more.

They are just stunning; if only l knew the name.
I've tried twice to knock on the door at the house to ask them. The first time l don't think anyone was home and yesterday, when l walked home that way l tried again. There was a car in the driveway and l knocked a few times, but, no one answered the door so l won't disturb them again.
So now l'm asking you, my dear readers. Do any of you know the name of this flower.