Button Widget Default Colour

Hello. When I add a SO Button, the default colour is RED. There is no red anywhere in my site so this is a preset somewhere but I cannot find where. I’m aware that within the widget I can set my own custom colour, and hover colour, but I would like to know where I can change that red to my own custom colour. So that all buttons can be the same. I’m hoping there is somewhere to set a default button colour AND a default hover colour. Can anyone advise please? I’m using Site Origin Corp theme V 1.20.11. Thank you