I've changed my mind a bit.
I think the very first answer might be correct.
There are 7 ways to choose the colour in the middle
Then you can put one colour any other place and there are 5! ways to place the rest.
This allows for rotation but it does not allow for reflectionl
There are 6 axes of symmetry for divide by 6 and you might have athe correct answer.
\((7*5!)/6\)
\(\frac{7*5!}{6} = \boxed{140}\)
Thanks for reminding me of that \boxed command PM