This is a summer (Sha) fukuro obi in rokutsuu gara.
Fukuro Obi is double-layered single sided obi in which two separately woven surfaces and back pieces of cloth are stitched together. This type of obi is typically only worn at weddings or other formal occasions. Ro and Sha textiles, also called usumono, are thin, translucent fabrics used for summer kimonos. The main difference between Ro and Sha is how they are woven.
Gara refers to the orientation, arrangement, and surface area of the patterns and pertains to a specific trend and obi tying style. The Rokutsuu gara type derives from a specific tying style, the Otaiko musubi. The areas of the obi that are visible in this style are patterned while the parts that are obscured are left blank. In terms of surface area, roughly sixty percent is patterned while forty percent is left blank.
Dark cyan fukuro (single-sided) Sha obi with interwoven gold and silver (floral/foliage?) motif patterning.