I've had these for a number of years, and this was a project almost a decade in the making
I had a stuttering start on Aleph a number of years ago, but I wasn't happy with the paint scheme and lost momentum on the project. Compared to the official scheme, I've introduced more yellow and gold style non metallic models.
Speaking of the non metallic metals, it is quite a basic recipe for the gold/yellow - basically, baler brown with Skeleton Horde contrast on it. Then highlighted up with demonic yellow (army painter) and then mixing more white in before finally adding the pure white highlights. It works great on the smaller areas, but I probably need more practice for the bigger areas!