title: ios Charts change grid lines color
body: <p>I have made a small application measuring Heart Rate from iWatch. The chart is working as intended showing current heart rate, but I have several issues with the design. Below you can find the image of my chart and its setting in swift.</p>
  
  <p><a href="https://i.stack.imgur.com/yXBlT.jpg" rel="nofollow noreferrer">ios Chart</a></p>
  
  <pre><code>         //chart set up
          self.chtChart.delegate = self as? ChartViewDelegate
          self.chtChart.noDataTextColor = UIColor.white
          self.chtChart.noDataText = "Press Start button to display the chart"
  
          let set_a: LineChartDataSet = LineChartDataSet(entries:[ChartDataEntry(x: Double(Int(0)), y: self.valueHR)], label: "BPM")
          set_a.drawCirclesEnabled = false
          set_a.setColor(UIColor.systemPink)
          set_a.drawValuesEnabled = false
          set_a.lineWidth = 5.0
  
          //remove vertical grid and labels
          self.chtChart.xAxis.drawGridLinesEnabled = false
          self.chtChart.rightAxis.drawLabelsEnabled = false
          self.chtChart.xAxis.drawLabelsEnabled = false
  
          //change label 'BPM' color
          self.chtChart.legend.textColor = UIColor.white
          //change left numbers (bpm values)
          self.chtChart.leftAxis.labelTextColor = UIColor.white
          //change right border line color
          self.chtChart.rightAxis.axisLineColor = UIColor.white
          //change left border line to white
          self.chtChart.leftAxis.axisLineColor = UIColor.white
  
          //change values from decimal to int on left axis
          let fmt = NumberFormatter()
          fmt.numberStyle = .decimal
          fmt.maximumFractionDigits = 0
          fmt.groupingSeparator = ","
          fmt.decimalSeparator = "."
          self.chtChart.leftAxis.valueFormatter = DefaultAxisValueFormatter.init(formatter: fmt)
  
          self.chtChart.data = LineChartData(dataSets: [set_a])
  </code></pre>
  
  <p>As you can see, my chart does not have the bottom border and I also can't change the color of the grid line inside the chart (I want to change it to white). I have tried following commands but nothing was changed:</p>
  
  <p><code>self.chtChart.xAxis.axisLineColor = UIColor.white
  self.chtChart.borderColor = UIColor.white
  self.chtChart.xAxis.gridColor = UIColor.white</code></p>