The first time Tauriel sees Kíli after the Battle of Five Armies (not the real first time, but the first time she's seen the dwarf without blood all over her face and a gaping gut wound demanding medical attention), she almost doesn't recognize the dwarrowdam.
The still and watchful figure at Thorin's left hand, only a step down on the dais on the opposite side of her older brother, is dressed in a deep green tunic and trousers such a dark gray they blend into the still mostly unlit halls of Erebor that can be seen behind the throne, a far cry from the tattered and filthy black outfit that Kíli had worn during all of their previous encounters. The dwarrowdam even has a surcoat of dark brown over the tunic and the armor it surely conceals, but the addition of color to Kíli's wardrobe is not the most stunning part of the sight.
No, that honor goes to the intricately braided crown of hair that has replaced what might previously have been honorably termed the mop on Kíli's head. Tauriel can tell even from this distance that the braiding in Kíli's hair is intricately arranged and patterned so as to resemble the crown that now rests on Thorin's head, metallic and bejeweled beads and other ornaments cleverly woven in to further the illusion.
As the Elven company approaches and Tauriel begins to see better in the fainter light of the halls under the mountain, she can watch the expressions play out over Kíli's face as Kíli recognizes her among the sizable escort that Thranduil had brought in an attempt to prove something in his bitter and utterly impossible to understand rivalry with the King Under the Mountain. Surprise and quickly veiled joy flit across Kíli's still stubbled face before it returns to what seems to be a passable mimic of Thorin's current scowl, broken only by a quick wink that Tauriel knows is aimed at her.
She inclines her head slightly in response and ignores the curious look Legolas shoots at her, his blue eyes as piercing as his arrows are. Perhaps one day she'll explain it to him, but for now this is something she will keep between herself and Kíli.