Conditional formatting can be removed in two ways:
A) Deleting formatting rules
When you delete a formatting rule, it will be removed from all cells to which it has been applied, regardless of which cells are currently selected in the worksheet.
Proceed as follows:
| 1. | Choose the ribbon command Home | group Format | Conditional formatting | Manage rules. |
| 2. | A dialog box appears. |
| Note: By default, this dialog box displays only the rules for the current cell (or selection). If you want to see all rules created in the entire worksheet instead, set the option Source to Current worksheet. |
| 3. | Select the rule to be deleted in the Rules list. |
| 4. | Click on the Delete button. |
The selected rule will now be deleted – and thus removed from all cells it affected.
B) Removing all conditional formatting from a cell range
There's another method for removing conditional formatting, which removes all conditional formatting from the selected cells.
Proceed as follows:
| 1. | Select the cells from which you want to remove all conditional formatting. |
| 2. | Choose the ribbon command Home | group Format | Conditional formatting | Delete rules in selected cells. |
(Alternatively, choose Home | group Contents | Delete  and select Conditional formatting, which does exactly the same thing.) |
This will "free" the selected cells from any conditional formatting rules applied to them.
All formatting rules that are no longer in use will be deleted automatically.