Blue Pigmentation in my 4k monitor

I was wondering if there was a fix for this. I doubt it would be an easy one nor a cheap one. I bought this monitor for 150$ on Ebay and nothing else is wrong with it. The pigmentation is a slight dark blue that tends to show up in darker/black backgrounds and is only really a minor nuisance. If anyone would have any ideas to a fix for this Id be really appreciative. thanks!

Pic: https://gyazo.com/cf8d262c743df355281d673daf54fdca