Need more info:
1) How big r the ryukins?
2) How long uv kept them? When did color change start? How long it took to change?
3) How big is ur tank? 4x2x2? Wat else in the tank? Wat filter?
4) Wat anti-chlorine u use? other additive?

For color change, usually the first culprit is the water. Either not stable/matured. or too hi NO3. or too hi Phosphate. Hv u checked n tested the water? watsmore ur using "well water"? hmm... questionable... do u drink/cook with the well water? or bathe in it also?

First time hear of using well water.

PS. where do u get live blood worms? where u located?

Happy investigating