Panel 1: We accompany an image of Teenage Elly bowing her head down over the sink and pouring the contents of a measuring cup over her hair with Present Day Elly saying that a teenager in love does some bizarre things. As by way of example, she remembers that she wanted Colin to notice her so badly, she decided to dye her hair.
Panel 2: When Connie asks her if she used a rinse, Elly says that she used food coloring. This, I think, was to avoid the inevitable "you can wear makeup when you're older and I'm dead" speech women of Marian's generation made when children decided for some silly reason that's a boy they'll forget a week later that they HAD to wear makeup.
Panel 3: As we look at Teenage Elly admire the results of her dying her hair what would have to be even darker, Present Day tells Connie that she poured red food dye over her scalp until she was convinced that it was a perfect shade of henna. Since Elly's memory makes everything pale violet, we don't actually know what happened but I don't think that she thought things through.
Panel 4: When Connie asks if that actually worked, Elly says "Let's just say I was a red head."
Summary: What Elly left out is slightly more important than what she left in.....namely, why she was trying to get Colin to notice her. My guess is that the reason that he didn't notice her is that he was in a relationship with a natural red-head and Elly thought that by changing herself, he'd see her the way she saw him. Being an impostor to catch a man might work in the shortest term but over the long run, no one likes living with an actress.