chore(sidebar): use unified theme color

Author: AGDholo

packages/hedgehog-lab/src/components/SideBar/SaveButton.tsx

@@ -7,19 +7,14 @@ import DialogContent from '@material-ui/core/DialogContent';
 import DialogContentText from '@material-ui/core/DialogContentText';
 import DialogTitle from '@material-ui/core/DialogTitle';
 import { createStyles, makeStyles, Theme } from '@material-ui/core/styles';
-import { purple } from '@material-ui/core/colors';
 
 const useStyles = makeStyles((theme: Theme) =>
   createStyles({
     save: {
       width: '50%',
-      backgroundColor: purple[500],
       fontSize: '0.875rem',
       fontWeight: 500,
       color: 'white',
-      '&:hover': {
-        backgroundColor: purple[700]
-      }
     }
   })
 );