ENGCOM-669: Pass Expected Data Type in backgroundColor Call (2.3) #13917

 - Merge Pull Request #13917 from northernco/magento2:2.3-backgroundColor-param-type-fix
 - Merged commits:
   1. ef0de42
   2. 64ecbe5
   3. 5915143

Author: magento-engcom-team

app/code/Magento/Swatches/Helper/Media.php

@@ -211,7 +211,7 @@ protected function setupImageProperties(\Magento\Framework\Image $image, $isSwat
         if ($isSwatch) {
             $image->keepFrame(true);
             $image->keepTransparency(true);
-            $image->backgroundColor('#FFF');
+            $image->backgroundColor([255, 255, 255]);
         }
         return $this;
     }

app/code/Magento/Swatches/Test/Unit/Helper/MediaTest.php

@@ -158,6 +158,7 @@ public function testGenerateSwatchVariations()
         $this->imageFactoryMock->expects($this->any())->method('create')->willReturn($image);
         $this->generateImageConfig();
         $image->expects($this->any())->method('resize')->will($this->returnSelf());
+        $image->expects($this->atLeastOnce())->method('backgroundColor')->with([255, 255, 255])->willReturnSelf();
         $this->mediaHelperObject->generateSwatchVariations('/e/a/earth.png');
     }