Suddenly this symbol came & stay as it is what it wants to tell plz explain...It is on left top to the wifi symbol

My S20+ display suddenly it got light pink /green without any visibility ... after few hours it work normally then again it went white pink fully...Samsung mobile you have not rights to play the emotions of people who give you their hard-earned money...

Shocked S20+ gets hang up...This msg shown & open app gets closedSometimes it takes time to unlockPlease tell me what to do?

My suggestion to Samsung please add feature to take a screenshot with 2/3 fingers slide down or something more easy as screenshot by gesture feel more complicated