Measured by eye rather than by number: the perceived difference (CIEDE2000) says how far apart two skeins still look once they are stitched. Under two, nobody will see that something other than 974 went into the cloth. That is where you start when a shop is out of a reference.
This shade is one of the 483 the converter can put in a pattern. Give it a photograph and it picks the threads for you, this one included when the picture calls for it.
No published chart uses this one yet.