How to give specific color in specific area? As shown below, the yellow color appears only on both edges, I have tried vertex color for the yellow, but I can't give another color in node editor.

Is it possible to give specific color on specific area?
You can assign any one material to a face at a time. However, you can apply a uv image to the object. This will allow you to paint freely on the object in as much detail as you wish.