I'm pretty new to making soft plastics, but I've started dipping my own tubes. The problem I keep running into is that the color is too transparent. Is this because of a lack of color or possibly because of how thin the tubes are? Any help would be greatly appreciated.

It could be either.  A lot of my colorants are translucent so no matter how thick I make the baits you can still see through them.  You'll just have to try dipping them another time and or add more colorant.  How many drops of what color are you using per oz of plastisol?

Depending on the color, around 2 drops per ounce. Darker colors seem to be more potent though.