In 2004, Topps introduced black refractors to Heritage, numbered the the last 2 digits of the year they were reproducing, and they've been a mainstay in the set ever since. Except for 2017 when they switched to blue for some reason, you could rely on black bordered refractors being a good source of value as they are tough enough to be challenging but not so rare that people don't actively chase sets or their particular players or teams. It's been 16 years so far, and it's a consistently popular parallel. That brings us to 2020, reprinting the black-bordered 1971 set. Obviously, having black border refractors in a black bordered set is going to present a unique challenge in making them stand out. As I see it, they could do 4 things with the chrome cards:
1) Make the base chrome and refractor cards with white and silver (or other) borders, and keep the #/71 cards black
2) Make the #/71 cards a different color, or even a pattern
3) Keep the #/999, #/571, and #/71 tiers all black but differentiate in the picture area or lettering somehow
4) Not make a #/71 parallel
I'd suppose #4 is not really an option. I am guessing #1 is what will happen. This is kind of lame, because I would want the purity of the base chromes being essentially as close to the base set as possible, but I'm not sure what else they'd do with borders. Black or not-black seem to be the options. Based on recent history, #2 could be the way they go. However, the black in the borders of these refractors doesn't really refract, so it would be hard to differentiate between flat black chome and a rainbow finish black chrome, so the #/999 and #/571 tiers won't really look too different if they keep with black on all tiers. So that's where #3 could come in. They've colorized the picture boxes of various other sets like Topps Chrome or Bowman Chrome, while keeping the standard borders, but they have never done that with Heritage.
I'm putting way too much thought into this. I've been worried about this since 2004, and now it's almost upon us.