Hamilton has expanded its Jazzmaster Open Heart collection with a pair of new dial colours. One is green and the other is midnight blue with a sparkling finish.

Available in two sizes and with several strap options, the watches are priced from £990.

Hamilton has added a pair of new colours to its Jazzmaster watch series, including one green dial and one with a blue texture inspired by a type of quartz.

First is the green model, which is available in a 42 mm case and with several strap options, including a five-link bracelet and a brown leather strap.

But arguably the more interesting addition to the Jazzmaster Open Heart family is the blue model. This is available in 36 and 42 mm case sizes, and has a finish that Hamilton says is inspired by aventurine, a form of translucent quartz with sparkles of mica.

As with other variants of the Jazzmaster, both new watches have the Open Heart dial design that gives a glimpse at the automatic mechanical movement within. There’s also an exhibition case back on the rear for an even better look at the H-10 caliber mechanism, which has an impressive 80 hours of power reserve and a Nivachron balance spring for protection against magnetism.

As with the green dial, the blue version is available on a five-link stainless steel bracelet or a leather strap, in this case colour-matched to the midnight blue dial. The dial is protected by a sapphire crystal and Hamilton says the watch has 50 metres of water resistance, so it’s safe to shower and swim with but shouldn’t be taken to any serious depth.