How can i illuminate an object?

I dont know almost anything about unity sorry if it is really simple. I have a sphere that i was working with and it is almost finished but now i have change the background to a black one and the sphere is not longer visible, I think i have to give it some light but i dont want it to seem illuminated. I mean i dont want to put a light near it because it gives the object a different color. Is there a way to illuminate the object itself with a component or something?

 

You can switch the material to use an Unlit shader.