\(
\displaystyle f(z) = \frac{1}{2} z^2
\)
\(
\definecolor{coral}{rgb}{0.9372549019607843, 0.403921568627451, 0.0}
\definecolor{turquoise}{rgb}{0.1568627450980392, 0.7450980392156863, 0.7333333333333333}
\boldsymbol{
\textcolor{turquoise}{\mathrm{Re} f}
} \; | \; \boldsymbol{\textcolor{coral}{\mathrm{Im} f}}
\)