UPDATE: 10 minutes after i figured out other way, but its useless , since it colors all my other fields. I have a lot of forms , so i need only fields colored in my global_content block. So this CSS isnt helpin

input[type=text] {
background-color: black;
color: red;
}
Also I have another question , is it possible to set default field value ? For example , it shows User in the username field , after you click on it , it disappears...as in FormBuilder. Thanks for answers!