On the DNA tab of a person's data entry page, you can record a related group from Y-DNA test results. For example, see this example results page for the name BEASLEY:
This is intended to pull together people who are as yet unlinked in the family tree but who are associated with other people in the same test results grouping. Then having these people associated may help with the goal of finding the linkages in those as yet unrelated people.
Each color grouping from the DNA results website would be defined as a separate grouping here, and anyone testing into that group could be assigned to that group. In the entry page, all existing groups will show in the dropdown list. If a group does not yet exist, click the button to add a new group:
Displaying & Searching
Once defined and linked to a person, this displays as an optional section at the bottom of their main page.
Clicking the linked group name goes to the page showing the full details of the group and all people assigned to that group. Then from there is a link to display all Y-DNA groups for that surname.
In the search page is an option to search by DNA Group Name, returing all people in that group.