Are penile cancers usually a particular color, or do they look different in every case?

Usually similar. Penile cancers often have a similar appearance but may have may vary. Typically they will be erythematous (red) lesions on the foreskin or glans of the penis and maybe ulcerative. The only way to determine if a lesion represents a cancer is to have a biopsy.
They can be. Various colors. They are usually a mass on your penis. They require a physician to evaluate them.