Most YouTube reviews state the back looks like a pure white, and the side rails look silver, or have a champagne hue to them in certain light. Even the men YouTube reviewers seem to always comment on how great the starlight looks. Like you, I like the silver/white phones as well
You have to remember that Apple changes it’s white on almost every phone. My silver XS is considered white, but it’s actually a darker silvery white which can be seen when placed next to a bright white object. I guess my point is, if you place every white iPhone next to each other, they are all going to look different. The real difference in the starlight color is the rails. The back will just look white unless you place it next to a bright white object.
The following video compares the silver (white) Pro model with starlight. They look pretty similar, and both look a shade of white to me.