First off, select add floor object from add light object.
Now go to objects>>primitive>>platonic. With your mouse,
drag your object above the plane.

In the materials window, go to file>>new material. Change the colour to
whatever you like. I chose green. Check off the box beside reflection. Click on
reflection, and set the brightness at about 25%. Check off the box beside
specular, and use the settings below:
Drag you material to your platonic item under the objects window. Make
another material of a different colour for the background. Hold down the add
light object button, and select the add light object button.
In the attributes window, under general, set the shadow to soft. Create
another light and place it on the other side of the object. Go to
render>>render settings. Set the antialiasing at best. In the multi-pass
section, check off enable multi-pass rendering. Hold down the channels button
and select add all. In the output section, set the size at about 475X360. Now go
to render>>render to picture viewer. You're done! Here is the finished
image:

Or, you can use the same steps with a sphere instead of a platonic object: