In the Material/Color Change dialog, there is a field called Color Model/Type. Here, you will find three options: Predefined,Texture or RGB Color.
Predefined: There are around 60 different predefined colors and materials. You cannot add your own materials and colors to the predefined ones in the same way as you can with RGB colors.
Texture : These are images of real materials. You can use them to make surfaces look more realistic. The textures include wallpapers, bricks and tiles. The textures must be stored on your PC or on your company's network in order for you to be able to use them.
RGB Color : You specify an RGB color by entering values for red, green and blue. There are 36 existing RGB colors in the program. You can easily add to these by creating your own RGB colors.