@aitcheff - For the reasons
@PanEuropean has said, only white lighting is permitted for forward facing lighting on cars in the UK (I see your location is Redhill, Surrey in the UK), other than forward facing turn signals / indicators which are orange. So yes, you will have imagined your car’s light bar being illuminated in blue.
The exception to the above would be emergency services vehicles that can have coloured forward facing lighting - e.g. blue or green flashing lighting (usually mounted in the radiator grille or door mirrors), or rotating roof mounted beacons that are only used to warn other road users of their presence in an emergency response situations.
For a general member of the public to fit coloured lighting would be illegal, and may also invalidate their insurance, potentially giving the insurance company the opportunity to decline to pay claims.
I personally aren’t a fan of the current trend of fitting forward facing light bars to cars. I see that Mercedes also fit them to some of their cars (I dare say there are other car manufacturers that do too). IMHO they are a bit gimmicky - that’s just my opinion though, and no doubt many mk8 Golf owners whose cars have a light bars will really like them which is fine by me
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