Cannot change the background color

If you are trying to change the background color of a certain element and background-color: #XXXXXX !important; did not work, try the following :

.selector {
     background: linear-gradient(to bottom, #XXXXXX 100%, #XXXXXX 100%) !important;
}

Change the XXXXXX value with the HEX code of the desired color.

Source: https://developer.mozilla.org/en-US/docs/Web/CSS/linear-gradient