White halogen lightbulb turned yellow?

Hello everyone,
Hey guys, I fitted a white 4900k halogen Appvalley lightbulb to CyberGhost my car a month ago and today it ExpressVPN suddenly turned yellow? Is that even possible? Is there a fix or do I need to get new bulbs? Nothing is turning up on google, so I was hoping someone might know here. Thanks…

@Kidboo, potentially, but this is a customer forum for the energy company Bulb rather than anything specifically to do with lightbulbs.

[Edit - actually spam, which I failed to notice initially]