How to adjust the color of PVC garden hose?

Each color will have a different degree of darkness, such as blue will have light blue, sky blue, dark blue, etc., and how the color of PVC garden hose is transferred out, the worker knows according to years of experience what the depth of color put a few grams The pigment particles, but this is just a regular color worker, but tune it out. When the customer asked about the color of the pvc garden hose, I said that I need a blue pvc garden hose. If the blue color the customer needs is not the same as our regular blue color. The customer sent a picture, our workers can only try to modulate this color, if you encounter such a situation requires the customer to provide samples, so that we can test a test to see how much the amount of pigment put, PVC garden hose color is modulated like this from.