There is only one grey color, the swatch from jiangjiang and the bag from Hillary Duff are the same grey color.
Also, Goyard does not do seasonal colors (pink as an exception, which is not always available, but could better be called 'limited edition'). Grey is in their core collection and is available all year round.
There has never been a black/grey canvas, all the items you see with grey dots on black canvas, are fake. Goyard uses white, brown and dark brown dots to create their black Goyardine canvas.
Hope this helps!