Excel has a strong and often missed feature, called Conditional Formatting, which allows you to format a cell depending on a rule [it's value]. This can be very useful for worksheets like Product Quantities and Dates. Let me show you what I mean.

Lets start off with a simple chart of products quantities in the warehouse.

We’ll want to mark the products that are low in stock (under 15) so a re-order can be done.

Let’s Start…

1. Start by selecting the rows you want to apply formatting to.

2. Let’s open the Conditional Formatting menu, and open a New Rule

3. Here, we define our formatting rules. We’ll define cells that their value is less than 15. Copy the following form -  Do not click “OK” yet.

4. Now after we’ve defined our formatting rule, we need to choose the formatting options to use on those cells:

- Click the “Format” button in the previous form.

Under the Fill tab, select red.

Under Font, select the color white.

Press OK twice. You should now see your cells colored:

As we can see, this is very simply and highly effective. There are many custom rules already defined if you don’t want to use “Custom” rules.