Feature Enhancement: add color property of the pop up label

Classes/BEMSimpleLineGraphView.h

@@ -325,6 +325,9 @@ IB_DESIGNABLE @interface BEMSimpleLineGraphView : UIView <UIGestureRecognizerDel
 /// Color of the pop up label's background displayed when the user touches the graph.
 @property (strong, nonatomic) UIColor *colorBackgroundPopUplabel;
 
+/// Color of the pop up label's text displayed when the user touches the graph.
+@property (strong, nonatomic) UIColor *colorTextPopUpLabel;
+
 
 /// Position of the y-Axis in relation to the chart (Default: NO)
 @property (nonatomic) BOOL positionYAxisRight;

Classes/BEMSimpleLineGraphView.m

@@ -154,6 +154,7 @@ - (void)commonInit {
     _colorPoint = [UIColor colorWithWhite:1.0 alpha:0.7];
     _colorTouchInputLine = [UIColor grayColor];
     _colorBackgroundPopUplabel = [UIColor whiteColor];
+    _colorTextPopUpLabel = [UIColor darkTextColor];
     _alphaTouchInputLine = 0.2;
     _widthTouchInputLine = 1.0;
     _colorBackgroundXaxis = nil;
@@ -375,6 +376,7 @@ - (void)layoutTouchReport {
                 self.popUpLabel.text = mString;
                 self.popUpLabel.textAlignment = 1;
                 self.popUpLabel.numberOfLines = 1;
+                self.popUpLabel.textColor = self.colorTextPopUpLabel;
                 self.popUpLabel.font = self.labelFont;
                 self.popUpLabel.backgroundColor = [UIColor clearColor];
                 [self.popUpLabel sizeToFit];