So I executed:
int elements[2] = {COLOR_HIGHLIGHT,COLOR_HIGHLIGHTTEXT};
DWORD newColors[2];
newColors[0] = Color::IndianRed.ToArgb();
newColors[1] = Color::Maroon.ToArgb();
SetSysColors(2,elements,newColors);
I thought it might do what I hoped it wouldn't.. but it did so now everything I select looks like this:
What are the default values for my system to set it back to how it was? I am running Windows 10.
Quoting MSDN:
However, this function affects only the current session. The new colors are not saved when the system terminates.
Just reboot your machine.