Aluminum oxidation of the border should be uniform, in the same component color uniform; borders, scratches, knocks, and injury defect, outside a meter at any angle not prima facie
Oxidized aluminum frame should be uniform, uniform color on the same assembly; border scratch, knock injury, bruises defect, one meter is not apparent from any angle
Oxidation in the aluminum profile frame should be uniform, in the same assembly unified color; border scratch, knock injuries and bruises defects, one metre away from any angle is not obvious