Not even a sentence into this post, and I have to come clean.
There is no such thing as a Buckeye Cardinal.
However, the Red-crested Cardinal does exist. Actually from the tanager family of birds, it certainly looks like a cardinal. And one could argue it's primary colors are scarlet and gray.
Hence, the Buckeye Cardinal.
These birds are common on the island of Kauai. Quite inquisitive, a pair would visit each morning while I was sitting outside reading.