[BUGFIX] fix replacement of color in inline-svg

The new optimizer replaces '#FFF' with 'white', that's why the old
replacement method does not work any more

inline-svg-template.mustache

@@ -15,7 +15,7 @@ ${{prefix}}{{{variableName}}}: "{{{inline}}}" {{width}} {{height}};
 @mixin inline-svg($name, $color: null) {
 	@if ($color) {
 		$color: str-replace($color + '', '#', '');
-		background: transparent url(str-replace(nth($name, 1), '%23FFF', '%23' + $color)) no-repeat 50% 50%;
+		background: transparent url(str-replace(nth($name, 1), 'white', '%23' + $color)) no-repeat 50% 50%;
 	} @else {
 		background: transparent url(nth($name, 1)) no-repeat 50% 50%;
 	}