Unfortunately, Excel doesn't have a direct way to validate data based solely on cell color formatting rules. Data validation typically works with conditions on the cell value itself (text, numbers, dates, etc.) or selections from a dropdown list.

However, there are alternative approaches to achieve a similar outcome:

1. Conditional Formatting with Data Validation:

- Use conditional formatting to highlight cells based on specific color rules tied to your desired data criteria (e.g., red for invalid values).
- Then, implement data validation with a formula that checks if the cell's color matches the "invalid" format. This formula would use functions like `GET.CELL.COLOR(A1)` (replace A1 with your cell reference) to retrieve the color index and compare it to the known index of your "invalid" format.
- While not directly validating based on color, it uses color as a visual cue and restricts input based on that cue.

2. Combine Conditional Formatting and Input Messages:

- Set up conditional formatting with specific color rules for valid and invalid data.
- Use data validation with an "Input Message" feature. This message can be customized to display instructions or warnings based on the cell's current color format.
- This approach provides both visual feedback and informative messages to guide users towards entering valid data.

3. VBA Macros (Advanced):

- For more control, you can create a VBA macro that triggers upon cell modification.
- The macro can access the cell's color using the `Interior.ColorIndex` property and compare it to the expected color for valid data.
- If the color doesn't match, the macro can display an error message or even prevent the invalid data entry.

While these methods don't directly validate based on color formatting alone, they offer workarounds to achieve a similar goal and provide feedback to users regarding data validity.