I'm familiar with BM Windham Cream and I agree that it is very yellow. There was a thread here recently with a link to a blog article about why the right white is so difficult to find, but I can't seem to find it. Maybe someone who reads this can find it.

This isn't the thread I was thinking of, but it has ideas to consider. Have you considered using a full spectrum paint?

Here is a link that might be useful: whites

How about BM Navajo White or Mayonnaise?
I just want to tone down the Windham Cream. Thanks for the helpful thread on whites, I really do want a yellow undertone, but not as bright as the Windham Cream is in my space.

I used BM Navajo White in a bathroom and it is a nice neutral. I also used BM Bone White which was a very close match to SW Antique White but I preferred the Bone White slightly different tone but so difficult to see the difference with the samples on the wall.

BM Bone white is a very close match to BM Wicker and is a very neutral happy color without being too tan or too yellow or too dark. It looks great with white trim. Do a search for my posting name and you will see pictures of my walls.