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.

In Microsoft Excel, if a cell contains a formula that results in an error, a triangle appears in the top-left corner of the cell. The triangle is an error indicator.

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.

How to create color scales in Excel If you prefer, you can also use color scales rather than data bars.