Add new test case in ColorTest.php

A new test case has been added in the ColorTest.php file to ensure the proper functioning of the HexToRGB function when converting the hex color value '#345'. This helps increase the test coverage for the Color class.

tests/ColorTest.php

@@ -41,6 +41,14 @@ public function testHexToRGB(): void
         $expectedResult = [140, 90, 69];
         $actualResult = Color::HexToRGB($hexColor);
         $this->assertEquals($expectedResult, $actualResult, 'Case 4 failed: #8c5a45');
+
+        // Test case 4: #8c5a45
+        $hexColor = '#345';
+        $expectedResult = [51, 68, 85];
+        $actualResult = Color::HexToRGB($hexColor);
+        $this->assertEquals($expectedResult, $actualResult, 'Case  failed: #345');
+
+
     }
 
     /**