This is caused by the Essentials plugin. Open "plugins/Essentials/config.yml" in a text editor, look for ops-name-color: 'c' and change it to ops-name-color: 'none' That should remove the red names.
heres the config for it and do you want them to have a color? ############################################################ # +------------------------------------------------------+ # # | Essentials (Global) | # # +------------------------------------------------------+ # ############################################################ # A color code between 0-9 or a-f. Set to 'none' to disable. ops-name-color: ''
ops-name-color: '4', thats what it will say in the essentials config by default, change it to ops-name-color: ' '