I believe that every modern scan software should give you an automatic option for scanning color negatives. I use a normal Canon scanner software driver which has four options in the 'Film' menu: color positives, color negatives, black and white positives and black and white negatives. No need to convert afterwards...

We do not see things as they are. ǝɹɐ ǝʍ sɐ sƃuıɥʇ ǝǝs ǝʍ