Currently, this failed flagging box is colored as informational (blue), not error (yellow), e.g.:
FR: Color the failed flagging box as an error, not as informational.
By contrast, informational boxes are typically in blue:
and error boxes are typically in yellow (at least with my browser config):
Not trying to nitpick but I sometimes use colors to avoid reading.
Note: Chrome's dark mode is on in these screenshots but that doesn't change the fact that the flagging box is using the same color as informational boxes.
Additional screenshot: this failed flagging box is also colored as informational (blue) on SO dark mode:




bug? I mean, I highly doubt it's intentional. Could be wrong, though.s-notice__warningclass to make it yellow. I've logged it as a bug for the team to dig into. It's likely a quick fix but fairly low priority since it's not preventing anything.