Red and green are complementary colors, so maybe using it is the drama's way of saying reflection of you?
I don't think the body dump is in the past, I think it's in the future. They show her cleaning up blood in her art studio and in that clip, the painting of her family was completed, but throughout the two episodes, it shows the painting as incomplete.
In terms of timeline, "Hannah" and HJ first met before HJ had her son. In episode 2, she mentioned that her son was going to kindergarten, which makes him around 4-5 years old -- does that mean that many years have passed since they've seen each other? WJ was admitted to the Ireland hospital on March 18th, 2018 and the marriage certificate says September 19th, 2013.
HJ and WJ must have had an affair because in the preview for next week's episodes, the hand grabbing -- I'm suspecting are between the two of them. If the translation is correct, HW says that "he" ruined me, meaning WJ, right? She married him and found out that he was cheating on her with HJ? I'm curious to know what "that incident" was that both of them do not want to openly talk about.
The exhibit that's going to be on display at the same time as HJ's, it seems like it'll be WJ's exhibit. He was a sculptor so I'm assuming those statues are his.
If this drama goes full on makjang, Hannah and HW are twins so that's why they can be in two places as once. And HJ's son is the love child between her and WJ.