Set up stores with same theme and different css Magento 2

Question

My multistore is setup as

shop
|-app
|-lib
|-pub
|-var
|-website1
 |-app*
 |-lib*
 |-pub*
 |-var*
 |-index.php
|-website2
 |-app*
 |-lib*
 |-pub*
 |-var*
 |-index.php

Where app*, pub*, ... are symbolic links to the folders in shop and the index.php files are set to run the two different websites.

Both website1 and website2 are configured to use the same theme, but I want them to use different colors and so I need them to use two different .less files (_block1.less and _block2.less) instead of the common one /shop/app/design/frontend/Venustheme/yume/web/css/magento/_block.less they are using now.

Is there a way to do this with the stores set up as they are?

Answer 1

I obtained what I needed creating a new theme as explained in the magento documentation (probably obvious, but I'm still learning).

The second store is configured with the new theme, which inherits everything from the one I wanted to modify, except the web/css/magento_block.less file.