More variables, harder problem
The more variables you have, the harder the problem is, also in design.
Working with shades is easier than working with different colors.
Working with textures is easier than working with textures and colors.
Working with shapes and form in one color is easier than working with shapes and form in many colors.
It's easier to start with the simpler approach, and slowly add more variables, to experiment if they improve things, always ready to backtrack if the simpler solution was better.
Our ego can lead us towards wanting more complex solutions, but real skill is in restricting ourselves to do so.