code: public ColorRecord getColorRecord (int classId, int colorId)
      {
          ClassRecord record = getClassRecord(classId);
          if (record == null) {
              // if they request color class zero, we assume they're just
              // decoding a blank colorprint, otherwise we complain
              if (classId != 0) {
                  log.warning("Requested unknown color class",
                      "classId", classId, "colorId", colorId, new Exception());
              }
              return null;
          }
          return record.colors.get(colorId);
      }
docs: Looks up the requested color record.