Solution dyed yarn color correction

An apparatus to change the color of a yarn, comprising:

• a hopper and an extruder, wherein the hopper is configured to control a rate of flow of a plurality of polymer flakes into the extruder;
• at least one sensor configured to communicate a signal comprising at least one value of a photonic property of the plurality of polymer flakes;
• a fluid injector configured to inject a color concentrate into the plurality of polymer flakes;
• and
• a processor, wherein the processor is configured to receive the signal and to make at least one adjustment to the fluid injector based on the received signal.

An apparatus to produce a yarn having a consistent color, comprising:

• a hopper and an extruder, wherein the hopper is configured to control a rate of flow of a plurality of polymer flakes into the extruder;
• at least one sensor configured to communicate a plurality of signals, wherein each signal comprises at least one value of a photonic property of the plurality of polymer flakes, and wherein each value is associated with a time;
• a fluid injector configured to inject a color concentrate into the plurality of polymer flakes;
• and
• a processor configured to receive the plurality of signals and process the values, wherein the processing of the values comprises,
• storing at least two values with their associated times,
• averaging the at least two values to produce an average value, and
• comparing the average value with a default value;
• and
• make at least one adjustment to the fluid injector based on the comparison.