\input{umtest-preamble} \usepackage{unicode-math} \setmathfont[script-font = {Asana Math}, script-features = {Style=MathScript,Colour=FF0000}, sscript-font = {Cambria Math}, sscript-features= {Style=MathScriptScript,Colour=0000FF}] {XITS Math} \begin{document} \[123456789^{123456789^{123456789}}\] \end{document}