Below is my code. How do I add a background colour to the first row (only the first row, please)?

```
\begin{table}[!htb]
    \centering
    \begin{tabular}{c c c}
        \toprule
        \textbf{Temperature} [K] & \textbf{Thickness}$[\mu m]$ & \textbf{Permittivity}\\
        \midrule
        $H \# /k$ & K & 17762 \\
        \bottomrule
    \end{tabular}

```