"Would you as developer appreciate variations in the buildings, knowing that their are more to choose from, either in color or details?"
Trying to answer to that, I'd say that definitely. Having variations, and some randomness makes a lot of things more lifelike, like for example, houses in a village presenting small differences between them offer a better illusion of a real town.
But, what about creating components that can be mixed on the fly? I experimented with that in a little kids game I offered here on itch.io. I have a multitude of little components that I mix programatically so every house or ground 'component' presents little differences to the others generated around.
And theoretically, the same can be done with colours. You can determine a game of palettes for those components so when making use of random generation they keep some similarity in style/colour.
A different thing (related to this subject I think) I tried to work with in another project I have in development, is being able to change colours in a sprite on the fly, following the style of old RPGs as those made by SSI (Champions of Krynn f.e.) or like in Knights of Legend, where you determine colours for different parts of the sprite.
But it's some work I must say, and the best approach I was able to find was making a list of 'special' colours that programatically can be interchanged when looking for pixel by pixel with colour similarities on the sprite. In other words, having an index of colours to be used to know what pixels to change. And some multiple-sprite approach in the middle... if possible.
I think I'm talking too much, but in fewer words, if you are interested in offering a good amount of variations of buildings or other elements, what about random generators? Maybe that could make you save time on the long run...
Well, I hope... because a random generator imply using an engine or code. But components and instructions of where should they be placed on the main image can be all graphics and would not depend of any engine at all.
I hope this answers helps a bit!
Good luck!!