Welcome to the Do-It forums VTfishing.
Listed in the Do-It store in the plastic colorant section showing the X2 colors you'll find a basic "drops per 4 ounce" batch for each of the colors in the listing. This drop count is only for the X2 colorants. Other colorant makers, M-F or Spike It for example, will require higher drop counts to get a full, rich color. People really have to find their own drop counts for their own personal finished color preferences. If you read back posts and threads regarding colors and recipes for colors you see a lot of reference to keeping a notebook handy to list the exact number for drops of colorant when developing a color recipe. A notebook is handy in that you'll have immediate recall for re-creating a color. But as for a universal recipe for colors? Nada....except for black.