I recently started injecting soft plastic baits, and before I invested in a tub of plastisol, I bought a few packs of brand name plastics to re-melt. The first runs looked amazing, but as I continued to shoot, the colors became progressively more dull. For instance, after five re-melts of junebug became a smoky black and blue.

Did you keep a close eye on temps? I believe heat stabilizer helps with discoloration when reheating multiple times.

 

Some manufactures baits dont remelt well. Working with fresh plastisol is much easier.

Too many reheats, too much heat can cause lots of issues.  It is really noticeable on white and chartreuse.

 

Heat stabilizer and an infared thermometer will help.