How do colors & highlighting work now?
The color you see when you move your cursor over a player or their name will tell you a lot about them. Here is a quick breakdown of the colors:
BLUE - Innocent
GREY - Aggressor or Criminal
RED - Murderer
GREEN - Fellow guild member
ORANGE - Rival guild member

How will an Innocent highlight if they cast Polymorph?
They will highlight as GREY for the duration of the spell.

What color will NPCs highlight as?
All NPC’s will highlight as BLUE unless they are a murderer.

…creatures?
Pets of Innocent Players will highlight as BLUE, animals will be GREY and monsters will be GREY.

…ghosts?
The same color that they died under.

What happens if a person is both an aggressor and a member of my guild? Will they highlight as GREY or GREEN?
Here is the precedence order:

Murderer
Rival Guild
Aggressor or Criminal
Fellow Guild Member
Innocent