The flag of the former county of Buskerud, Norway. Its design is shared with the county arms, and shows a blue bear, constituting an expression of Buskerud's vast expanses of mountains and forests, among which Vassfaret in particular has been known for its populations of bears. The ursine's striking colouration is a reference to the Blue Colour Works in Modum, where cobalt ore was mined, and blue pigment produced from it. For a time, the works were the largest of their kind in the world—the fruits therefrom once made up 80% of the global market, and constituted a pertinent export.
The white background of the flag carries symbolism too. Within heraldry, it is permissible to use white to depict silver, and on flags, this is even customary. Here, a white/silver background is used to represent the Kongsberg Silver Mines, and their massive mineral riches—operating between 1623 and 1957, their history spanned over 300 years. The flag was approved by royal resolution 1966‐04‐01.
Buskerud fylke, flagg – Arkivverkets digitale fotoarkivForskrift om fylkesvåpen og fylkesflagg, Buskerud fylke – LovdataAbout us – BlaafarveværketFylkets historie – Buskerud fylkeskommuneFYLKESVÅPEN – Graphic charter of Buskerud County Municipality
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(Sources of the oldest file version:)

Based on File:..Buskerud Flag(NORWAY).png and File:Buskerud våpen.svg
Hallvard Trætteberg, vectorization by VulpesVulpes42
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(Authorship information for the oldest file version:)

PNG flag by AlexR.L. (CC-BY-SA 3.0)Coat of arms by SKvalen (PD-Norwegian CoA)SVG flag by SiBr4