I would really look at the price for unfinished white oak treads.

If this is a production builder, you won't be able to get them to swap them out for you. If you are using a custom, or perhaps a semi-custom, builder, you might just have to do some homework for him or her.

Basically you will never get red oak to look like white oak, especially in a light color. In a dark color, maybe. But then why would you need white oak??

"prefinished engineered white oak floor"

What finish is on this floor? Pictures? Making red oak look like white oak is a tough task to start with, prefinished white oak will make it even tougher.

Does your floor manufacturer make a matching stair cladding? If you do that, you don’t need to have oak treads.

Another option is to do a beautiful contrasting color of stain on the stairs. You could pull the colors together with handrail or baluster or post colors. Adding a runner on the stairs, or painting the risers would give you more options to tie in the floor colors.

If you really want to match wood, dark stain is worth a try, but lighter colors are really tough. I matched a red oak transition strip to a dark chocolate brown stone tile once. I had to keep mixing and adding stain. It worked only because it was a dark brown color. It’s hard to neutralize red and yellow tones.

As everyone mentioned, it will never look like white oak. Put in white oak stair treads or paint it black.