Sure, I can help you with that! Here are the steps to plot multiple sets of data on a scatter graph in Excel:

1. Open a new Excel workbook and enter your data into three columns. Column A should contain the voltage data for each lighting system, column B should contain the current data for each lighting system, and column C should contain the lighting system names (red, green, or blue).
2. Select all three columns of data by clicking and dragging over the column headers.
3. Click on the "Insert" tab in the ribbon at the top of the screen.
4. Click on the "Scatter" chart type in the "Charts" section of the ribbon.
5. Select the first scatter chart option (with just dots, no lines).
6. Excel will create a scatter chart with all of your data points plotted. However, the data points for each lighting system will be the same color and shape, making it difficult to distinguish between them.
7. To fix this, right-click on one of the data points in the chart and select "Select Data" from the context menu.
8. In the "Select Data Source" dialog box, click on the "Add" button under "Legend Entries (Series)".
9. In the "Edit Series" dialog box, enter a name for the series (e.g. "Red Lighting System").
10. Click on the "Series X values" box and select the voltage data for the red lighting system.
11. Click on the "Series Y values" box and select the current data for the red lighting system.
12. Click "OK" to close the "Edit Series" dialog box.
13. Repeat steps 8-12 for the green and blue lighting systems, entering a name for each series and selecting the appropriate voltage and current data.
14. Once you have added all three series, click "OK" to close the "Select Data Source" dialog box.
15. You should now have a scatter chart with three different series, each with its own color and shape. You can customize the chart further by adding axis labels, a chart title, or a legend.

That's it! You should now have a scatter chart with all three sets of data plotted on the same graph, making it easy to compare the voltage and current values for each lighting system.