Best fit PARSEC isochrone line on (a) V vs. (B − V) CMD and (b) V vs. (V − I) CMD of Czernik 30. The black open circle symbols are the member stars of Czernik 30, the blue open circles indicate the RC stars of Czernik 30, the gray dots are nonmember stars but located inside the radius of Czernik 30 and the red lines are the best fit PARSEC isochrone model.