Entity reference additional field In D7 I have two new node type defined e.g. branch and leaf. The branch is a collection of leaves that I'm referring to using the entity_reference module. In the picture below the leaves are the nodes representing the colors. The leaves could be re-used in several branches.
Here is a picture of my collection 
I would like to add for each of the referenced leaves, two checkboxes to add some information about that leaf that is referenced in that branch. I have added on the picture manually the checkboxes. This is what I would like to achieve. Then, programmatically when I read the branch and all its leaves, I want to be able to retrieve the checkboxes value as well. Everything is working far, I just need to know how to add the leaves, so that at edit time when I edit a branch I can tick the checkboxes as needed.
How could I do that? If there is no module that exists, which hooks should I use for adding this fields to the referred leaf node in the branch?
I do not want to add new fields for the leaf node type, I need the new fields/chekboxes to be added to a branch for each leaf thus at the moment of referring to the leaf and for each leaf.
One of the ways to solve it is to use the Paragraphs module.
How to start with Paragraphs for Drupal 7
It's basically entity reference fields with layers.
You create a Paragraph field as a container for each data set, then within paragraph create fields for color and lists (checkboxes).
BTW why not upgrade to D8? D8 supports this type of structure better.