Zend certified PHP/Magento developer

Format a percentage-based single cell value in Excel

I want to do something that sounds to me pretty simple: I have a single cell which contains a percentage value. I want to somehow visualize the percentage in the cell: show a progress bar, change the color, something. All I could find is that you can do it when you have several cells. Then, you can use for example Color Scales or Data Bars, so that the lowest value cell will be colored green, the highest will be red, and the in between cells will be relatively colored somewhere between. But in my use case I only have one cell.

Could someone help?