The goal of counting arrangements: Count everything ONCE and ONLY ONCE.
Understand that once we choose the outer six, the center dot is automatic.
There are 6! ways to put the colors in any arrangement without considering overcounting. 6! = 720.
We must consider overcounting. Since there are 6 axes of symmetry, we divide 720 by 6 to get 120. The rotations of the arrangements also matter (Eg: [1,2,3,4,5,6, 7 in the center] is the same as [4,5,6,1,2,3, 7 in the center]), so we divide 120 by 2 to get 60. There is your answer, \(\boxed{60}\).
Hope this helps, (do not get confused by the answers above)
- PM