I’m testing charts framework usage, but i cannot understand how to show two values from same origin in the same chart. Here I built a fake example of a blood pressure app, where I would like to show in the same chart BOTH data of Systolic and Diastolic pressure. I tried different “forEach” but cannot understand how to correct two issues.

1 – values are of the same color.
2 – values are “linked” as they were same set of values.

what I want is a chart with two lines like this one, one for each value (in different color etc…):

but I get this:

struct MyBloodValue {
    var date: Date
    var systolic: Double
    var diastolic: Double
}


import SwiftUI
import Charts

struct ContentView2: View {
    @State var bloodPressureData: [MyBloodValue] = []
    
    var body: some View {
        VStack {
            Text("Blood Pressure Data")
                .font(.headline)
        
            Chart(bloodPressureData, id: .date) { data in
            
                LineMark(
                    x: .value("Date", data.date),
                    y: .value("Systolic", data.systolic)
                )
                .foregroundStyle(.purple)
                .symbol(Circle())
                
                
                LineMark(
                    x: .value("Date", data.date),
                    y: .value("Diastolic", data.diastolic)
                )
                .foregroundStyle(.blue)
                .symbol(Circle())
                
            }
            .chartForegroundStyleScale(range: [.green, .orange])
            .frame(height: 300)
            .padding()
            
        }
        .onAppear {
            self.bloodPressureData = self.generateTestData(count: 3)
        }
    }
    
    func generateTestData(count: Int) -> [MyBloodValue] {
        var testData: [MyBloodValue] = []
        
        let currentDate = Date()
        for i in 0..<count {
            let randomSystolic = Double.random(in: 100...125)
            let randomDiastolic = Double.random(in: 70...90)
            let randomDate = currentDate.addingTimeInterval(Double(-3600 * i))
            
            testData.append(MyBloodValue(date: randomDate, systolic: randomSystolic, diastolic: randomDiastolic))
        }
        
        return testData
    }
}

struct ContentView2_Previews: PreviewProvider {
    static var previews: some View {
        ContentView2()
    }
}