This question is related to this answer: https://tex.stackexchange.com/a/69525/13552.
The documentation for enumitem (on page 7 in Version 3.5.2 2011-09-28) says that
nextline: if the label does not fit in the margin, the text continues in the next line, otherwise it is placed in a box of width \leftmargin − \labelsep, i.e., the item body never sticks into the left margin. Sets labelwidth=!.
My goal would be to get all text to continue onto the next line regardless of the label's width.
Example
\documentclass{article}
\usepackage{enumitem}
%\setlist[description]{style=nextline} % Optional Global Setup
\begin{document}
\begin{description}[style=nextline] % Local Setup
\item [Green] The color green.
\item [Red] The color red.
\item [Yellow] The color yellow.
\end{description}
\end{document}


\item [Green] The color green.to\item [G] The color g.in your example code. one can see the effect you want to avoid. – Gonzalo Medina Aug 20 '15 at 18:42