Make the default element color for bright theming colors lighter

Signed-off-by: Julius Härtl <jus@bitgrid.net>

apps/theming/lib/Util.php

@@ -79,7 +79,7 @@ class Util {
 	public function elementColor($color) {
 		$l = $this->calculateLuminance($color);
 		if($l>0.8) {
-			return '#555555';
+			return '#dddddd';
 		}
 		return $color;
 	}

apps/theming/tests/UtilTest.php

@@ -105,7 +105,7 @@ class UtilTest extends TestCase {
 
 	public function testElementColorOnBrightBackground() {
 		$elementColor = $this->util->elementColor('#ffffff');
-		$this->assertEquals('#555555', $elementColor);
+		$this->assertEquals('#dddddd', $elementColor);
 	}
 
 	public function testGenerateRadioButtonWhite() {