Thats what i have done on almost a handfull of times on my collection to wich now i regret because 8.5 up is selling quite nicely in value of your collection.
Black in colour???? Never, it's a clear acetate card, it would only be black if it's background is black.
But there are yellow ones that people say its a gold version but there's no such thing as gold version. I think the acetate has just turned yellow over the years.