Sure, I can help you with that! Here's how you can delete the recently used font colors in Excel:

1. Click on any cell in the worksheet to activate the Home tab in the ribbon.
2. Click on the Font Color dropdown box in the Font group.
3. Hover your mouse over the color you want to remove from the recently used list. A small "X" will appear in the top right corner of the color box.
4. Click on the "X" to remove the color from the list.
5. Repeat steps 3 and 4 for each color you want to remove from the list.

That's it! The colors you removed should no longer appear in the recently used list. If you want to add a color back to the list, simply use it again in your worksheet and it will automatically be added to the list.