Some browsers show transparency as black or other colours. In image viewers it may also have something to do with your background colour of the viewer and if they support transparency.
Looking at your pictures closer it look like you have some sort of texture in the semitranparent part? Maybe that is what is showing up as fully opaque. It does look to be slightly lighter though.
Looking at your pictures closer it look like you have some sort of texture in the semitranparent part? Maybe that is what is showing up as fully opaque. It does look to be slightly lighter though.