🎨(react) enhance Modal component styles

update Modal token and css files with new css variables introduce
with the new tokens architectures

packages/react/src/components/Modal/index.tsx

@@ -99,7 +99,8 @@ export const ModalInner = ({ closeOnEsc = true, ...props }: ModalProps) => {
           <div className="c__modal__close">
             <Button
               icon={<span className="material-icons">close</span>}
-              color="tertiary-text"
+              color="tertiary"
+              variant="neutral"
               size="small"
               onClick={props.onClose}
             />