SwiftUI how to make List and Section transparent

I'm trying to make a list that looks something like this:

However no matter what I try, I can't figure out how to make both the List and the Sections have a .clear background, and it currently looks like this:

I have tried adding .background(Color.clear) to both the List and Section, with no luck. When I use any other color than clear, it does change just fine. But it seems like there's something "behind" that background color that makes it still show white and gray underneath...

How do I change this list to be completely clear?

Here is my current failed attempt:

var body: some View {
        NavigationView {
            List {
                ForEach(uniqueEntries, id: \.self) { category in
                    Section(header: HStack {
                        Text(category)
                            .font(.headline)
                            .foregroundColor(.white)
                            .padding()
                        Spacer()
                    }
                        .listRowInsets(EdgeInsets(top: 0, leading: 0, bottom: 0, trailing: 0))
                        .background(Color.clear)
                    ) {
                        ForEach(self.entriesCollatedByCategory[category]!) { entry in
                            ExpenseRow(entry: entry)
                                .listRowInsets(EdgeInsets(top: 0, leading: 0, bottom: 0, trailing: 0))
                                .listRowBackground(Color.clear)
                            
                                
                        }
                    }
                }
            }
            .padding()
            .background(Image("tempGradientBackground")
                            .resizable()
                            .aspectRatio(contentMode: .fill))
            .navigationBarTitle(Text("Budget"))
        }.background(Color.clear)
    }