Customized Opening Single and Double Quotes for a yinit Lettrine

Question

This post directly relates to egreg's answer given in size and alignment of quotation mark with lettrine

The following code

\RequirePackage{fix-cm}
\documentclass{book}
\usepackage{lettrine}
\usepackage{xcolor}
\setcounter{DefaultLines}{3}
\setlength{\DefaultFindent}{0em}
\setlength{\DefaultNindent}{.17em}
\renewcommand{\LettrineFontHook}{\usefont{U}{yinit}{m}{n}}
\renewcommand{\DefaultLoversize}{-0.67}
\newcommand\loq{%
  \sbox0{T}%
  \sbox2{%
    \dimen0=\csname f@size\endcsname pt
    \dimen0=0.5\dimen0 % adjust the factor to suit
    \fontsize{\dimen0}{0}\selectfont`%
  }%
  \llap{\raisebox{\dimexpr\ht0-\ht2}{\usebox{2}}}%
}
\begin{document}
\thispagestyle{empty}
\begin{LARGE}
\begin{center}
\begin{minipage}{5.75in}
%\baselineskip=1.5\baselineskip
\lettrine{\color{red}{\loq W}}{\color{red}{e}} \textbf{{\color{red}{cannot}} solve our problems with the same thinking we used when we created them.''}
\end{minipage}
\end{center}
\end{LARGE}
\end{document}

makes use of egreg's algorithm for defining the command \loq---which places a customized opening quote at the beginning of the lettrine.

I have run egreg's code, which worked fine for me; however, when I incorporated it into the above MWE, the opening quote does not appear:

The only thing I can see which might be causing the problem is I am using a different lettrine than the one considered in the aforementioned post. Of course, there could also be a problem with my code (which I am running with Pdflatex) which I cannot see.

QUESTION: How may the code in the MWE be modified in order to produce an opening single quote (red, in this case) before the lettrine; also, how may the algorithm be modified in order to produce an opening double quote?

Thank you.