How to don't modify the color of sprite ?

Hey everyone ! I’m new user of UE4 And i try by learn the 2d side. So i create a 2d paper and i add my sprite in the content browser. I regulate the color and after The object “Brightness color” change whithout explanation. If you have the answer i take him because i of on’t understand.

Thank you for your answers

https://www.noelshack.com/2018-12-2-1521578526-1.png

https://www.noelshack.com/2018-12-2-1521578528-2.png