I have legitimately never heard of that before, which is weird because I'm a dried chili pepper freak. I have bought lots of different brands of chili powders, and some are a lot brighter red or darker than others, but I've never heard of a recipe specifically calling that out. Pretty much every company is different in how they roast and blend (which you can see by looking at them), and they have different flavors because of that.
So now for some Google:
Apparently McCormick makes a "light" chili powder, as does Fiesta just based on a quick search. Both may only be available to food service, or online vendors though.
Edit: I just found this, which has good information;
Dark Chili Powder Vs. Light Chili Powder: PepperScale Showdown
After seeing that, I would just do the normal thing that I usually do, which is just pick a chili powder based on color, or what your personal preferences are. Like the article says, If you're doing something that you want milder, or want to have a brighter color, pick a lighter chili powder. I would say to go the store and look at whatever is in clear containers, and make your own judgment call. Don't get Badia brand, it's really dark.
Dunno, I almost exclusively use dried ground chiles that are just chiles and not blends, because I usually add Mex oregano, cumin, paprika (often smoked), epazote, chipotle, and whatever else separately anyway if that's what I'm going for. We like a lot of cumin, for example, and Mex oregano.