         //
         //  Draw the background blocks
         //
+        //  Note: This supports drawing backgrounds of alternating colors, every 3 hours on 3 hour boundaries. 
+        //      Currently, both colors are set to be identical.
 
         var nextXBoundary = floor(CGFloat(firstBoundarytimeOffset) * viewPixelsPerSec)
         print("first hour boundary at \(firstBoundarytimeOffset/60) minutes")

    private let mealLineColor = Styles.darkPurpleColor
    // Colors
    // TODO: add all graph colors here, based on Styles colors
    private let backgroundRightColor = UIColor(red: 0.949, green: 0.953, blue: 0.961, alpha: 1.000)
    private let backgroundLeftColor = UIColor(red: 0.918, green: 0.937, blue: 0.941, alpha: 1.000)
    private let horizontalLineColor = UIColor(red: 1.000, green: 1.000, blue: 1.000, alpha: 1.000)

    //

    // Basal data
    //
    private let basalBlueRectColor = Styles.blueColor
    private let basalLightBlueRectColor = Styles.blueColor
    private let kBasalMinScaleValue: CGFloat = 0.0
    
    //
