Looks like a royal blue but has a purple undertone in person. 

Length of thread on spool: 20m – 100% perlé silk. Price per spool.
Diametre of the thread is 0.526mm.
Presented on reusable ivory coloured plastic spools. Size of spool: diametre 2.5cm – length 4.8cm.

Made in France

Fil Au Chinois perlé silk thread is glossy and resistant. It is traditionally used for buttonholes as well as topstitching on fabric or leather.
It can also be used for cross stitch, bobbin lace or braids and trimmings. It was also commonly used in days gone by: in tapestries the finer details like the faces and hands of the figures, the centers of certain flowers or animals eyes were sewn with silk threads to obtain a contrast with the wool.