Talk:Sigils/@comment-7645613-20150108054335/@comment-50.101.56.248-20150108071726

That's because those ranks are Eagle, Silver Eagle, and Gold Eagle and share a design, differing only in colour. I haven't used the mastery sigil, but based on the two images of it, it looks like the border matches the actual sigil colour (white, silver, or gold) and the fill colour is selectable.

Your sigil's border should have changed from white to silver. This would be really hard to notice unless you were looking specifically for it, but compare what you have now to the image of the rank 18 one, which clearly has a gold border.