What is the best way to create a simple colored plane object in NGUI?

Now I’m developing a NGUI application in unity 4.3. In my application, I want to create a simple plane with color. So what is the best way to create a simple plane?
I think I don’t need to prepare plane colored texture, I just need some material with custom shader. Am I wrong?

Hierarchy > Create > Plane
Up on the tabs
Assets > Material > Shader-Diffuse> Give any color image you want on your plane
Drag this material to the plane