I was trying to change the typeface of some text that I wrote in a tikzpicture. I have tried a few things, but none of them seem to work. What I current have is

\begin{tikzpicture}[scale=0.4] \path [decorate, decoration={text along path, text={Sample Text}, text align={center}}] (-30,8) .. controls (-15,22) and (15,22) .. (30,8) ; \end{tikzpicture} 

but I would like to change the typeface to qag from the tgadventor font package. Does anyone know how I might be able to do this? I have also had difficulties changing the font colour.