Flag of Roden, the Netherlands. The colours yellow, red and blue are the colours in the coat of arms of the (knights of /) family Ewsum who had done a lot for Roden. Amongst the things they did, they have created a forest (hence the pine tree in the coat of arms). At one time in history, the trees were used as support beams for the mines in Limburg.
File:Flag of Roden, Netherlands.jpg
Own work