Prettify main view, add temperature history

TempTrack/Extensions/Color+Extensions.swift

@@ -0,0 +1,24 @@
+import Foundation
+import SwiftUI
+
+extension Color {
+
+    func blend(to other: Color, intensity: CGFloat = 0.5) -> Color {
+        Color(UIColor(self).blend(to: UIColor(other), intensity: intensity))
+    }
+}
+
+extension UIColor {
+
+    func blend(to other: UIColor, intensity: CGFloat = 0.5) -> UIColor {
+        let l2 = max(0.0, min(1.0, intensity))
+        let l1 = 1 - l2
+        var (r1, g1, b1, a1): (CGFloat, CGFloat, CGFloat, CGFloat) = (0, 0, 0, 0)
+        var (r2, g2, b2, a2): (CGFloat, CGFloat, CGFloat, CGFloat) = (0, 0, 0, 0)
+
+        getRed(&r1, green: &g1, blue: &b1, alpha: &a1)
+        other.getRed(&r2, green: &g2, blue: &b2, alpha: &a2)
+
+        return UIColor(red: l1*r1 + l2*r2, green: l1*g1 + l2*g2, blue: l1*b1 + l2*b2, alpha: l1*a1 + l2*a2)
+    }
+}