How to Make Colors Change With Validation in Excel. Excel's conditional formatting tool applies formatting depending on cells' contents. Validation rules can change cells font, style, size or border.

The default active cell format in Microsoft Excel isn't all that easy to see, but you can use this easy-to-implement code solution to change that.

To change Gridline color in Excel, use Excel Options, apply a custom-colored border to the cells, or apply a custom line color. Full details here.

Learn how to create a drop-down list in Excel without or with color using conditional formatting and data validation rules.