Forensic DyeConsumable 1
Source Pathfinder Advanced Player's Guide
Price 3 gp
Weight light
Activate 
Interact
Activating this vial of colorless liquid requires inserting a small amount of another chemical or material, such as blood or mud. The vial reacts rapidly, transforming into a murky, reddish-brown substance.
Once activated, the dye remains potent for up to 10 minutes, during which time you can spend 1 minute to brush it onto a single object of up to 1 Bulk or across the ground in a single 5-foot square. Where the dye comes in contact with an exact match for the activating chemical, it takes on a bright blue hue, while staying transparent in areas where there is no activating component present.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
AlchemicalAlchemical items are powered by reactions of alchemical reagents. Alchemical items aren't magical and don't radiate a magical aura.
ConsumableAn item with this trait can be used only once. Unless stated otherwise, it's destroyed after activation. Consumable items include alchemical items and magical consumables such as scrolls and talismans. When a character creates consumable items, they can make them in batches of four.