Good morning
I carried out the Hertzsprung-Russell diagram analysis for M67/NGC2682.
I reduced the data using PRiSMv10 advance as it has feature to analyze both for B band and R band fits images with allocated star catalog like UCAC4/USAO A2-2.0 simultaneously.
The data comes as text file for B and B-R values, which came with negative sign
, I converted them in positive by multiplying with -1 and calculated R mag simply by rule R=[B-(B-R)]. Finally plotted for R vs. B-R. really looks awesome... 
Vikrant, India