Here are few CSS hacks to customise your Moodle login page while using Edwiser RemUI theme.

Note: You need to add these CSS codes in Edwiser RemUI settings >> General settings >> Custom CSS section.

1) CSS to change White background to a different color in the right region.

#page-login-index .page-login-main {
background-color: #ccc;
}


2) CSS to change the color of Sign In and Remember username text.

#page-login-index label[for="rememberusername"] {
color: red;
}
#page-login-index .page-login-main > .font-size-24 {
color: red;
}


3) CSS to change the color of Login button.

#page-login-index #loginbtn {
background-color: red !important;
border-color: red !important;
}