Custom Admin Color Accent

<?php
add_action( 'admin_head', 'scseed_inject_accent_var' );
function scseed_inject_accent_var() {
    $color = sanitize_hex_color( apply_filters( 'scseed_admin_accent', '#7c5cff' ) );
    if ( ! $color ) { return; }
    echo '<style id="scseed-accent-var">:root{--scseed-ac:' . esc_html( $color ) . ';}</style>';
}

/* Applies the custom accent colour defined via the scseed_admin_accent filter */
#wpadminbar {
    background: var(--scseed-ac, #7c5cff) !important;
}
#adminmenu li.current a.menu-top,
#adminmenu li.wp-has-current-submenu a.wp-has-current-submenu,
#adminmenu li.wp-has-current-submenu .wp-submenu-head {
    background: var(--scseed-ac, #7c5cff) !important;
}
.button-primary,
input[type="submit"].button-primary {
    background: var(--scseed-ac, #7c5cff) !important;
    border-color: var(--scseed-ac, #7c5cff) !important;
}
#adminmenu a:focus {
    outline-color: var(--scseed-ac, #7c5cff);
}
.notice-info,
.notice-success {
    border-left-color: var(--scseed-ac, #7c5cff) !important;
}