Recently the mod label got a darker coloured border, as to better set it apart from the blue background that is used on a usercard when one is the OP. As was requested in this answer.
This leaves a bit of a discrepancy between the staff and mod labels, with one having a darker border than the other.
Looking at the CSS there is a small difference. Both border colours use a value of
[colour]-200, but the backgrounds use a value of
[colour]-100 for the orange colour, and the blue uses
[colour]-075. For the orange colour a value of
orange-075 doesn't exist, but this could explain the difference in contrast. Increasing the border colour of the orange from
-300 looks better I think.