Cut, laminate and attach vertically, each subject group with a string of ribbon to each color to create 4 different conference groups for each of the 3 subjects subject.
Use clothespins with students names to show which group they belong in. You can also write students name on each group with a Vis-à-vis marker after laminated.
This is great for transitioning into small group conferring. Students will know ahead of time which group they belong in and will help your day and lessons flow much more easily.