Add new offFillColor property.

Author: Boris-Em

Classes/BEMCheckBox.h

@@ -100,6 +100,10 @@ typedef NS_ENUM(NSInteger, BEMAnimationType) {
  */
 @property (strong, nonatomic) IBInspectable UIColor *onFillColor;
 
+/** The color of the inside of the box when it is Off.
+ */
+@property (strong, nonatomic) IBInspectable UIColor *offFillColor;
+
 /** The color of the check mark when it is On.
  */
 @property (strong, nonatomic) IBInspectable UIColor *onCheckColor;

Classes/BEMCheckBox.m

@@ -55,6 +55,7 @@ - (void)commonInit {
     _hideBox = NO;
     _onTintColor = [UIColor colorWithRed:0 green:122.0/255.0 blue:255/255 alpha:1];
     _onFillColor = [UIColor clearColor];
+    _offFillColor = [UIColor clearColor];
     _onCheckColor = [UIColor colorWithRed:0 green:122.0/255.0 blue:255/255 alpha:1];
     _tintColor = [UIColor lightGrayColor];
     _lineWidth = 2.0;
@@ -160,6 +161,11 @@ - (void)setOnFillColor:(UIColor *)onFillColor {
     [self reload];
 }
 
+- (void)setOffFillColor:(UIColor *)offFillColor {
+    _offFillColor = offFillColor;
+    [self reload];
+}
+
 - (void)setOnCheckColor:(UIColor *)onCheckColor {
     _onCheckColor = onCheckColor;
     [self reload];
@@ -224,10 +230,9 @@ - (void)drawOffBox {
     self.offBoxLayer = [CAShapeLayer layer];
     self.offBoxLayer.frame = self.bounds;
     self.offBoxLayer.path = [self.pathManager pathForBox].CGPath;
-    self.offBoxLayer.fillColor = [UIColor clearColor].CGColor;
+    self.offBoxLayer.fillColor = self.offFillColor.CGColor;
     self.offBoxLayer.strokeColor = self.tintColor.CGColor;
     self.offBoxLayer.lineWidth = self.lineWidth;
-    
     self.offBoxLayer.rasterizationScale = 2.0 * [UIScreen mainScreen].scale;
     self.offBoxLayer.shouldRasterize = YES;