Banner color applied to signature on replies

There seems to be a bug in that on receiving replies, there is a border around the original signature that is the color of the banner added to the incoming message. Below are a couple of examples. Note that these are on replies that are received (i.e. when I receive a reply from someone I originally sent a message to, my signature appears to have a border around it in the same color as the banner added to the reply message. Seems like it is only internal-facing issue since the banners are removed for external recipients, but it is a bit annoying visually for our internal team.