If I copy a table from Numbers to the pasteboard and then create a new document in Preview, it usually works fine, but if cells contain partially transparent background or border colors (especially within gradients), the alpha value is either not kept or it’s more opaque than anticipated.
Maybe this is a limitation of or issue with the PDF format that Preview defaults to, or of the underlying framework. Anyhow, I already reported a bug to Apple.
OS X 10.10.5, Preview 8.0, Numbers 3.5.3. I’m willing to upgrade if needed.
Meanwhile, is there a way to export a table to PNG while keeping alpha information intact using just system or free third-party tools?