bug fixes

Author: zhujinxuan

packages/ra-ui-materialui/src/list/datagrid/Datagrid.stories.tsx

@@ -139,8 +139,9 @@ export const RowSx = () => (
         <Datagrid
             rowSx={(record: any) => ({
                 backgroundColor: record.id % 2 ? 'white' : '#eee',
-                '& td.column-year':
-                    record.year > 1900 ? { color: 'primary' } : {},
+                ...(record.year > 1900 && {
+                    '& td.column-year': { color: 'primary.main' },
+                }),
             })}
         >
             <TextField source="id" />