this is going to be a Pain-in-the-neck request IF even possible .. but i'm just gonna say it,
imagine an endless ***cough--NOT--cough*** shades of all colors to create an ever close-to-realistic looking structures.
basic idea is a at the block converter there will be a special block recipe clicking on it will bring a small pop-up menu contains the HSB sliders to create any shade of color you want ... set the three sliders >>> click "OK" .. set how many blocks you want >>>> craft >>> end.

if you see no connection between having multiple shades of the same color and realism, just look at the ground for any biome .. imagine the entire ground having only one solid color like this race challenge map:

^ bad quality (taken from an old video)