Is a cranberry bad if it is red inside?

A cranberry that is red inside is generally not bad; in fact, it is normal for ripe cranberries to have a deep red color throughout. However, if the cranberry appears mushy, has an off smell, or shows signs of mold, it may be spoiled. Always check for overall freshness when evaluating fruit. If in doubt, it's best to err on the side of caution and discard any questionable cranberries.