Green text is not showing up, partially.
Reason for this is that Twitter adds Unicode directional control characters around @users names. When copypasting the text a lineshift was added before the end control char adding an hidden Unicode directional control end character before the >. This result in the line not starting with > but rather the hidden UTF-8 control char resulting in not making it greentext.
Next time I'll delete that @.
If you copy into notepad or similar you will see the control characters I talk about and can easily remove them. If you copy paste in textarea in browser you won't see them, but if you use arrow keys to "navigate" you will encounter a char that don't move cursor before and after the @user portion.
Thanks for the explanation but I can't see them, neither with Kate nor Gedit.
I'll delete the @ for sure next time.