Check out this tube of WLP400. It’s dated Oct 3, 2013 (so packaged June 3, 2013?)
Pretty sure it’s fine but I don’t think I’ve noticed a yeast slurry from White Labs that was two different colors. I shook it up and when it settled it went back to having the darker yeast clump together like in the picture.
I’d say it’s fine. If one layer was green or had tentacles, maybe not
Don’t know why that is but I’ve seen in that in a tube or two before and never had a problem that I could notice.
I’ve stopped questioning what yeast looks like. The last vial of Brett Trois I got looked more like it should have come from a sperm bank than a yeast bank. While what you have looks odd, there’s nothing about it that looks “bad” to me. Just roll with it.