Hi there,

You can apply css codes below on your custom.css file and see how it goes You can change them accordingly, if problem still persisted, it would be best if you can provide us with your backend and FTP access for further check on this issues.

/* For text area */

#es .is-editing .es-story-text, #es .is-editing .xes-story-textbox {

    background-color: #000000;

}



/* For font colors */

#es .mentions textarea {

    color: red;

}

Please give it a try and see how it goes.