Source : Webster's Revised Unabridged Dictionary (1913)

Tint \Tint\, v. t. [imp. & p. p. {Tinted}; p. pr. & vb. n.
   {Tinting}.]
   To give a slight coloring to; to tinge.

Source : WordNet®

tinting
     n : the act of adding a tinge of color; "the hairdresser gave
         her hair a modest tinting"