Stealth auras are sparkles that indicate that the object they are highlighting can be interacted with. They are a manifestation of a character's, typically a Cooper, thieving abilities; they can, however, highlight everyday objects, like buttons.
Stealth auras first appeared in the first job of Sly Cooper and the Thievius Raccoonus. Sly Cooper mentions that he sees the sparkles and Bentley, having read about this event, tells him that master raccoon thieves are able to sense "thieving opportunities which manifest themselves unexplainable blue auras." Despite this, when other characters are playable they each have their own visible auras of differing colors. Sly's ancestors, being raccoons, have blue auras.
Auras may appear on ledges and pipes, underneath tables and wagons, and in many other locations. If the auras are on a ledge, the player needs to hold (or tap in Sly Cooper: Thieves in Time) , and move either left or right. While near a pipe or any climbable object, however, the player must first jump with , then push . In various episodes after He Who Tames the Iron Horse in Sly 2: Band of Thieves and in the games following, there may be wall hooks that require the player, after hooking on with , to hold in the down position before tapping , allowing Sly or his ancestors to gain extra height.
Each playable character's auras correspond to their signature color; Sly's are blue, Bentley's are green and Murray's are pink.
Other available characters also have their own colored auras as well. The Guru's are purple, the Panda King's are yellow and Carmelita Fox's are orange. In Thieves in Time, the ancestor's stealth auras correspond to their trademark colors; Rioichi's are reddish brown, Tennessee's are yellow, Bob's are blue, Sir Galleth's are silver and Salim's are turquoise.
In Sly 2, Bentley was able to use his auras to sneak across buildings and crawl under tables. In Sly 3: Honor Among Thieves, however, he lost all of his aura abilities due to his being in a wheelchair, except for interactivity, like firing cannonballs in Galleon Duel.
The only thing Murray and Panda King can do with their auras is sneak around buildings (they are too big to crawl under tables). The Guru, on the other hand, can do all non-Cooper moves.
In addition to his aura abilities, in Menace from the North, eh! exclusively, when Sly was near an icy wall, he could jump and push , and his cane would split into two smaller canes. This ability is the only ability that does not have auras.
In Thieves in Time, auras do appear for Bob when he is near ice walls.