To apply color adjustments using the Polygonal Lasso:
1. Adjust the color settings on the left panel.
2. Click on the image to set the starting point.
3. Move the mouse to draw a first straight segment and click to set its end point.
4. Repeat to create additional segments.
5. Double-click to complete the polygon.
To apply different color adjustments to another part of the image, click on New Selection.