Google Sheets formula to highlight several checkboxes based on duplicates?

Question

Looking for a way to have checkboxes be checked if there is already a duplicate linked cell that is checked. For example, if there are 3 Red's in Column Color , if I were to check one row of Red, the other 2 would also be checked off.

Any help would be appreciated, thanks. A copy of the spreadsheet: https://docs.google.com/spreadsheets/d/1Z-YGS0pOE0tx7GUUCq0zm7VDXSOJl0PRGxaS713v0_4/edit?usp=sharing

Answer 1

formula to highlight several checkboxes based on duplicates

=COUNTIFS(B$2:B, B2, C$2:C, C2*1=1)>1