If Universal truths exist, we don't know any of them. Humanity cannot, period, be objective enough to construct a universally true concept.
When someone can tell me that the green they see is the green that the person next to them sees and prove it, then I'll be willing to concede that there are absolute facts. Otherwise, sorry, but no. I know that might hurt, to think that you can't be irrefutably right about something, but you're an individual in a sea of individuals. Everything is subjective, everything is different, and everyone sees differently from you.
Nothing is true, everything is permitted.