If I'm not mistaken, that was research in mice. Mice are nocturnal and do not likely have the same entrainment patterns with respect to blue (sky) light.

There are still valuable things that can be learned from that kind of research, but the popular coverage really missed the mark by directly extrapolating from research in mice to human circadian rhythms.

According to research I've found, red light will raise cortisol but not suppress melatonin production. Blue light does both. Don't remember which paper, but I found this one suggesting that blue light is worse than regular white light (which includes the blue spectrum) at suppressing melatonin: https://onlinelibrary.wiley.com/doi/abs/10.1034/j.1600-079X....