I want to get this:
[![enter image description here](https://i.stack.imgur.com/DPWhC.png)](https://i.stack.imgur.com/DPWhC.png)

I wrote this, when I put `[-1.5ex]` after `\\`, I can get reduced row height but the color of the row is still normal row height. How can I make the color's height reduce? Any suggestion?

```
\begin{tabular}{|c|c|c|}  \hline 

h & 0.00003 m&  0.00003 m\\\hline  
\rowcolor[rgb]{0.7,0.7,0.7} &  & \\[-1.5ex]\hline   
n & & \\\hline

\end{tabular}

```

The output: [![enter image description here](https://i.stack.imgur.com/bQKJK.png)](https://i.stack.imgur.com/bQKJK.png)