I have same problem too.
but you can setup .opacity(0.5) , will show background color(with opacity).
TextEditor(text: $text)
.background(Color.red)
.foregroundColor(.black)
.opacity(0.5)
.padding()
if you want more red you can try
TextEditor(text: $text)
.background(
ZStack {
Color.red
Color.red
Color.red
Color.red
Color.red
Color.red
}
)
.foregroundColor(.black)
.opacity(0.5)
.padding()