You can use conditional formatting with color scales to visualize data trends in Excel. Here's how:

1. Select your data range: Choose the cells containing the data you want to analyze for trends.

2. Go to Conditional Formatting: Navigate to the "Home" tab on the Excel ribbon. In the "Styles" group, click the dropdown arrow under "Conditional Formatting."

3. Choose Color Scale: From the dropdown menu, hover over "Color Scales" and select the desired color scale format. Excel offers various pre-set options with two or three colors, representing a range from low to high values.

4. Customize the color scale (Optional): If you want to adjust the color gradient or specific thresholds, click "More Rules" at the bottom of the color scale options. This opens the "Format Cells" window with a "Formatting Rules" tab. Here you can:
- Change the color gradient: Click on the color gradient bar and select different colors for minimum, midpoint (if applicable), and maximum values.
- Edit the color scale type: You can choose between sequential (one color transitions to another), diverging (two contrasting colors for opposite ends of the spectrum), or a specific color scale.
- Set minimum and maximum thresholds: Define the data values that correspond to the lowest and highest points of the color scale.

5. Click OK: Once you've applied your desired formatting, click "OK" to close the formatting windows.

Now, your data will be displayed with a color gradient. Cells with lower values will have the color corresponding to the minimum end of the scale, while higher values will transition towards the color representing the maximum value. This visually highlights trends and helps you easily identify areas with high or low values within your dataset.