\input{umtest-preamble}
\usepackage{unicode-math}
\begin{document}
\newcommand\ARRAY[4]{%
  \begin{array}{cc}
  #1 & #2 \\ #3 & #4
  \end{array}}
\def\test{\[
 \left.\left[\ARRAY a b c d\right]
 \middle\slash
       \left[\ARRAY 1 1 1 {\mathsf 0}\right]
 \right. \]}
\setmathfont
  [slash-delimiter=frac]{Cambria Math}
\setmathfont
  [range={\mathsfup},
   Color=0000FF]
  {STIXGeneral}
\test
\setmathfont
  [slash-delimiter=frac,
   range="2044,
   Color=FF0000]
  {Cambria Math}
\test
\end{document}