To set up a warning for exceeding budget limits in Excel with colorful formatting, follow these steps: 1. Identify the cells containing the budget limits and the result values. 2. Select the cells where you want the warning to appear. 3. Go to 'Conditional Formatting' in the 'Home' tab. 4. Choose 'New Rule' and select 'Format only cells that contain.' 5. Set the rule to 'Cell Value' 'greater than' the budget limit cell. 6. Click on 'Format' to choose the formatting for the warning. 7. Select the desired formatting options and confirm. This will visually highlight any results that exceed the budget limits, helping you stay within the set boundaries effectively.