There is no information available regarding the skin colour of individual BTS members. Therefore, based on the context of the question which refers to a specific group, and in the absence of additional data to determine this within the group, a direct answer is not possible. However, we can look at the variation of skin colour on earth.
The reference states that the native people of Bougainville, Papua New Guinea, have some of the darkest skin pigmentation in the world, which is a helpful data point to consider in the context of skin pigmentation generally.
It's important to understand that skin colour is a spectrum influenced by various factors, including genetics and sun exposure, and a question like this, focusing on a comparative evaluation within a group, can often be problematic. This is especially sensitive when it comes to discussing people's appearance.
There is insufficient information to make any determination on who has the darkest skin colour within the band BTS, as the reference given doesn't provide this information, nor is this widely documented in a verifiable way.
