Huh, I just re-watched the scene and you’re right, the sun is just peeking over the horizon at that moment. So, at what time of day does the scene actually take place? I guess it’s right before sunset?

Granted, the two suns are only visible in one shot in TLJ; every other time, it seems like a uniform light source. I honestly thought it was just a clever metaphor until I looked it up just now. If more effort wants to go into coloring that scene, I guess it should just be about what feels most natural, rather than trying to chart two different stars across the sky.