As a swift action, you can enable or disable the ability to detect magic.

While enabled, you can see the presence of magic auras:

• On any creature or object currently affected by a magical abiliity
• One any area where a magical effect is currently active
• On any object which is a magical item
• On any creature which has manifested a magical ability within the last round

As a standard action, you can analyze any particular magical aura, and determine the following:

• The rank of the magical ability
• The amount of mana manifested in the ability (if applicable)

More class-specific differences TBD. Ex:

• Witch: chroma
• Warlock: planar affinity