The worst that could happen, to my knowledge, from a ringneck bite is an itching sensation that occurs for a couple hours. No one has really tested venom on humans(any volunteers lol?), but ringneck snakes rarely bite.
Here are the ringneck snake sub-species/morphs I know of...
Albino Northern Ringneck Snakes
Aberrant Northern Ringneck Snakes(spots on the neck ring)
Anerythristic Northern Ringneck Snakes
Albino Regal Ringneck Snakes
Melanistic Pacific Ringneck Snake
Albino Prairie Ringneck Snake
Hypomelanistic Prairie Ringneck Snake
Pied Prairie Ringneck Snake
Albino Southern Ringneck Snake
Albino Key Ringneck Snake
Albino NorthWestern Ringneck Snake
There might be more, but these are the only ones I know of just using memory.