reverted test to correct for new background correction

Author: ggoneiESS

tests/test_utils.py

@@ -24,11 +24,7 @@ def test_GIVEN_invalid_WHEN_validating_line_edit_THEN_line_edit_turns_red():
 def test_GIVEN_valid_WHEN_validating_line_edit_THEN_line_edit_turns_white():
     line_edit = DummyLineEdit()
     validate_line_edit(line_edit, True)
-    assert (
-        "background-color: "
-        + ("#333333" if os.uname().sysname == "Darwin" else "#FFFFFF")
-        in line_edit.stylesheet
-    )
+    assert ("background-color: #FFFFFF" in line_edit.stylesheet)
 
 
 def test_GIVEN_valid_WHEN_validating_line_edit_with_tooltip_THEN_line_edit_tooltip_is_changed():