What you're talking about is "trade secrets", the universal means for keeping your company intellectual assets away from competition before patent was invented. If the patent process is not reformed and simply decays away, trade secret will be the preferred technique once again.
Because the letters and numbers by themselves are not intellectual property. That's like banning a handgun because someone might use it for an unlawful purpose. The gun is an instrument...neither good nor bad. How it is used determines legality.
To use your examples, restraining use of the Hex code would be like KFC preventing anyone from using the word "chicken" or Coca-Cola claiming exclusive rights to the word "sugar" because the particular ingredients are part of the respective recipes.