how to change the colour of this background

It’s an inline style. Just change the preferred color from the following tag:

<p class="has-text-align-center has-black-color has-text-color has-background has-medium-font-size" style="background-color:#(Preferred color)">...</p>

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)