The South Korean tech giant released its flagship smartphone in two colour variants, black and white. However, a blue Galaxy S4 was spotted being sold in Japan.

The smartphone's predecessor, Samsung Galaxy S3, is available in no less than six color versions: Pebble blue, Marble white, Sapphire black, Amber brown, Titanium grey and Garnet red.

An "arctic blue" Galaxy S4 has been spotted in NTT DoCoMo promo materials, which suggest the handset should be launched in the coming weeks in Japan, alongside the black and white editions. By all means, we should expect the blue S4 to be introduced in other markets around the world at some point. And why not, other colors, too.

The Samsung Galaxy S4 features a 5-inch Super AMOLED screen offering full 1,920 x 1,080p HD resolutions with a 441p image density. Retaining the same height as the Samsung Galaxy S3, the new model is actually thinner than its predecessor at just 7.9mm thick in comparison to the 8.3mm measurements of the Galaxy S3.

Running Android 4.2.2 Jelly Bean, the Samsung Galaxy S4 has a 13-megapixel camera in the rear coupled with a 2-megapixel snapper in front. The flagship packs a whole host of new camera features like Dual Camera and features Samsung Galaxy Smart Scroll, Smart Pause, Air View and Air Gesture functionality.

With a 2,600mAh battery, the Samsung Galaxy S4 has three internal storage size options, all bolstered by the addition of a microSD card slot supporting cards up to 32GB. The current quad-core version of the Samsung Galaxy S4 provides 4G LTE connectivity as well as IR LED, Wi-Fi and Bluetooth.

Meanwhile, Samsung is rumoured to release the Samsung Galaxy S4 Mini in July, according to SamMobile.

Samsung said nothing about the S4 Mini during the Galaxy S4 launch event in March. But, the timing of Galaxy S4 Mini release comes about three months after Galaxy S4 completes a global debut. That seems to correspond with the 2012 Galaxy S3 release, which was followed by smaller version of S3, just three months later. The S3 sold in millions around the world, pushing up Samsung to stand close to Apple's iPhone.

Based on cues that Galaxy S4 Mini will debut in the 29th week, the launch date will fall between July 14th and 20th. The launch will probably be global. Samsung is expected to make an official announcement of other members of the Galaxy S4 family - S4 Mini, S4 Activ and S4 Zoom - at the CTIA 2013 event scheduled to take place from May 20th to 23rd.

A new report claimed that the Samsung Galaxy S4 Mini will be released with Galaxy S4 Zoom and Galaxy S4 Activ. However, Samsung has no official comment on the rumours on its smartphones.