This shirt is a western-style shirt in pale yellow, often called a cowboy shirt, characterised by pearly snap buttons and chest flap pockets with pointed flaps. 

Here are the key details:
Style: Long-sleeve western shirt, an iconic garment whose style originates from the 19th-century Wild West.

Features: It has snap buttons (often pearly) for quick fastening, as well as shoulder yokes (decorative seams) and chest flap pockets, typical elements of this style.

Colour and Material: The item is yellow/cream and made of cotton, common materials for these shirts to combine comfort and durability.

The Undrground brand mainly offers premium streetwear, notably t-shirts and hoodies.