I didn't mean anything else than a gold ring, but I suppose a golden ring could mean a ring with only the color of gold but not really made of gold.
In the context of jewellery, that's a good assessment of the way things should be. I think rings with zero genuine gold content, though, would generally be described as "gold-coloured" rings, assuming the person doing the describing wanted to be honest.
In practice there are very few rings that are gold-coloured but contain no gold. Most are either gold-plated or, slightly better, gold-filled. In both cases there is some genuine gold content, albeit very low. Both of these types of ring are often still referred to as "gold rings", not "golden" or "gold-coloured", but the hallmark or lack of one, in the UK at least, will alert you to the fact that there is likely to be negligible gold content.