Yes, you can use the COUNTIF function in Excel to count cells that meet a certain criteria, including cells with a specific fill color. Here's how:

1. Select the range of cells you want to count.
2. Click on the Home tab in the ribbon at the top of the Excel window.
3. Click on the Conditional Formatting button in the Styles group.
4. Choose Highlight Cells Rules and then More Rules from the dropdown menu.
5. In the New Formatting Rule dialog box, select Use a formula to determine which cells to format.
6. In the Format values where this formula is true field, enter the formula
   Formula:

   =CELL("color",A1)=1 

   (without the quotes), where "A1" is the first cell in your selected range. This formula will highlight any cells in the range that have a fill color of red.
7. Click on the Format button and choose a fill color to use for the highlighted cells.
8. Click OK to close the Format Cells dialog box, and then click OK again to close the New Formatting Rule dialog box.
9. Now that you've highlighted the cells with a certain fill color, you can use the COUNTIF function to count them. For example, to count the number of cells with a red fill color, enter the formula
   Formula:

   =COUNTIF(A1:A10,CELL("color",A1)=1) 

   (without the quotes), where "A1:A10" is the range of cells you want to count.

Repeat the above steps for each fill color you want to count. Just make sure to change the formula in step 6 to for green, for blue, and so on.