diff --git a/packages/common/src/core/__tests__/slickGrid.spec.ts b/packages/common/src/core/__tests__/slickGrid.spec.ts
index 305832902..15c5311e4 100644
--- a/packages/common/src/core/__tests__/slickGrid.spec.ts
+++ b/packages/common/src/core/__tests__/slickGrid.spec.ts
@@ -1159,6 +1159,15 @@ describe('SlickGrid core file', () => {
 
       expect(rowSelectSpy).toHaveBeenCalled();
     });
+
+    it('should clear previous selection model when calling setSelectionModel() with a different model', () => {
+      const cellSelectionModel = new SlickCellSelectionModel();
+
+      grid = new SlickGrid<any, Column>(container, [], columns, { ...defaultOptions, darkMode: true });
+      cellSelectionModel.init(grid);
+
+      expect(cellSelectionModel.cellRangeSelector.addonOptions.selectionCss).toBe('2px solid white');
+    });
   });
 
   describe('Node Getters', () => {
diff --git a/packages/common/src/extensions/slickCellSelectionModel.ts b/packages/common/src/extensions/slickCellSelectionModel.ts
index 5be04a1a6..6acd03872 100644
--- a/packages/common/src/extensions/slickCellSelectionModel.ts
+++ b/packages/common/src/extensions/slickCellSelectionModel.ts
@@ -32,7 +32,7 @@ export class SlickCellSelectionModel implements SelectionModel {
     this._eventHandler = new SlickEventHandler();
 
     this._selector = (options === undefined || options.cellRangeSelector === undefined)
-      ? new SlickCellRangeSelector({ selectionCss: { border: `2px solid ${this._grid.getOptions().darkMode ? "white" : "black"}` } as CSSStyleDeclaration })
+      ? new SlickCellRangeSelector({ selectionCss: { border: '2px solid black' } as CSSStyleDeclaration })
       : options.cellRangeSelector;
 
     this._addonOptions = options;
@@ -52,6 +52,10 @@ export class SlickCellSelectionModel implements SelectionModel {
 
   init(grid: SlickGrid): void {
     this._grid = grid;
+    if (this._addonOptions === undefined || this._addonOptions.cellRangeSelector === undefined) {
+      this._selector = new SlickCellRangeSelector({ selectionCss: { border: `2px solid ${this._grid.getOptions().darkMode ? "white" : "black"}` } as CSSStyleDeclaration })
+    }
+
     if (grid.hasDataView()) {
       this._dataView = grid.getData<CustomDataView | SlickDataView>();
     }